Fix helix/rev2 not working properly when using split_common. (#16512)

When helix/rev2 was using split_common, it didn't work properly and I couldn't type on the right hand side.

The cause is that the following code, added in 0.16.0 to `quantum/keyboard.c`, does not include `quantum/split_common/split_util.h` but instead includes `keyboards/helix/rev2/split_util.h`. Therefore, `split_pre_init()/split_post_init()` in `quantum/split_common/split_util.c` was not called.

```c
  #ifdef SPLIT_KEYBOARD
  #    include "split_util.h"
  #endif
```

1 files changed, 0 insertions, 92 deletions

diff --git a/keyboards/helix/rev2/split_scomm.c b/keyboards/helix/rev2/split_scomm.c
deleted file mode 100644
index 378781b98c..0000000000
--- a/keyboards/helix/rev2/split_scomm.c
+++ /dev/null
@@ -1,92 +0,0 @@
-#ifdef USE_SERIAL
-#ifdef SERIAL_USE_MULTI_TRANSACTION
-/* --- USE flexible API (using multi-type transaction function) --- */
-
-#include <stdbool.h>
-#include <stdint.h>
-#include <stddef.h>
-#include "split_scomm.h"
-#include "serial.h"
-#ifdef CONSOLE_ENABLE
-  #include "print.h"
-#endif
-
-uint8_t volatile serial_slave_buffer[SERIAL_SLAVE_BUFFER_LENGTH] = {0};
-uint8_t volatile serial_master_buffer[SERIAL_MASTER_BUFFER_LENGTH] = {0};
-uint8_t volatile status_com = 0;
-uint8_t volatile status1 = 0;
-uint8_t slave_buffer_change_count = 0;
-uint8_t s_change_old = 0xff;
-uint8_t s_change_new = 0xff;
-
-SSTD_t transactions[] = {
-#define GET_SLAVE_STATUS 0
-    /* master buffer not changed, only recive slave_buffer_change_count */
-    { (uint8_t *)&status_com,
-      0, NULL,
-      sizeof(slave_buffer_change_count), &slave_buffer_change_count,
-    },
-#define PUT_MASTER_GET_SLAVE_STATUS 1
-    /* master buffer changed need send, and recive slave_buffer_change_count  */
-    { (uint8_t *)&status_com,
-      sizeof(serial_master_buffer), (uint8_t *)serial_master_buffer,
-      sizeof(slave_buffer_change_count), &slave_buffer_change_count,
-    },
-#define GET_SLAVE_BUFFER 2
-    /* recive serial_slave_buffer */
-    { (uint8_t *)&status1,
-      0, NULL,
-      sizeof(serial_slave_buffer), (uint8_t *)serial_slave_buffer
-    }
-};
-
-void serial_master_init(void)
-{
-    soft_serial_initiator_init(transactions, TID_LIMIT(transactions));
-}
-
-void serial_slave_init(void)
-{
-    soft_serial_target_init(transactions, TID_LIMIT(transactions));
-}
-
-// 0 => no error
-// 1 => slave did not respond
-// 2 => checksum error
-int serial_update_buffers(int master_update)
-{
-    int status, smatstatus;
-    static int need_retry = 0;
-
-    if( s_change_old != s_change_new ) {
-        smatstatus = soft_serial_transaction(GET_SLAVE_BUFFER);
-        if( smatstatus == TRANSACTION_END ) {
-            s_change_old = s_change_new;
-#ifdef CONSOLE_ENABLE
-            uprintf("slave matrix = %b %b %b %b %b\n",
-                    serial_slave_buffer[0], serial_slave_buffer[1],
-                    serial_slave_buffer[2], serial_slave_buffer[3],
-                    serial_slave_buffer[4] );
-#endif
-        }
-    } else {
-        // serial_slave_buffer dosen't change
-        smatstatus = TRANSACTION_END; // dummy status
-    }
-
-    if( !master_update && !need_retry) {
-        status = soft_serial_transaction(GET_SLAVE_STATUS);
-    } else {
-        status = soft_serial_transaction(PUT_MASTER_GET_SLAVE_STATUS);
-    }
-    if( status == TRANSACTION_END ) {
-        s_change_new = slave_buffer_change_count;
-        need_retry = 0;
-    } else {
-        need_retry = 1;
-    }
-    return smatstatus;
-}
-
-#endif // SERIAL_USE_MULTI_TRANSACTION
-#endif /* USE_SERIAL */