Remove useless "ifdef KEYBOARD_*" (#20078)

Co-authored-by: Nick Brassel <[email protected]>

keyboards/maple_computing/lets_split_eh/eh/eh.c

@@ -1 +0,0 @@
-#include "lets_split_eh.h"

keyboards/maple_computing/lets_split_eh/eh/eh.h

@@ -1,7 +1,5 @@
 #pragma once
 
-#include "lets_split_eh.h"
-
 #include "quantum.h"
 
 #define LAYOUT( \

keyboards/maple_computing/lets_split_eh/lets_split_eh.c

@@ -1,4 +1,4 @@
-#include "lets_split_eh.h"
+#include "quantum.h"
 
 #ifdef SWAP_HANDS_ENABLE
 __attribute__ ((weak))

keyboards/maple_computing/lets_split_eh/lets_split_eh.h

@@ -1,7 +0,0 @@
-#pragma once
-
-#include "quantum.h"
-
-#ifdef KEYBOARD_maple_computing_lets_split_eh_eh
-    #include "eh.h"
-#endif