Remove useless "ifdef KEYBOARD_*" (#20078)

Co-authored-by: Nick Brassel <nick@tzarc.org>

keyboards/boston_meetup/2019/2019.c

@@ -13,7 +13,7 @@
  * You should have received a copy of the GNU General Public License
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
-#include "2019.h"
+#include "quantum.h"
 
 #ifdef RGB_MATRIX_ENABLE
 #include "rgb_matrix.h"

keyboards/boston_meetup/2019/2019.h

@@ -1,19 +0,0 @@
-/* Copyright 2019 ishtob
- *
- * This program is free software: you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation, either version 2 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program.  If not, see <http://www.gnu.org/licenses/>.
- */
-#pragma once
-
-#include "boston_meetup.h"
-

keyboards/boston_meetup/boston_meetup.c

@@ -1,2 +0,0 @@
-#include "boston_meetup.h"
-

keyboards/boston_meetup/boston_meetup.h

@@ -1,7 +1,7 @@
 #pragma once
 
-#ifdef KEYBOARD_boston_meetup_2019
-    #include "2019.h"
+#include "quantum.h"
+
 #define LAYOUT( \
     K00, \
     K10, K11, K12, K13, \
@@ -14,6 +14,3 @@
   {  K20,  K21,   K22,   K23    }, \
   {  K30,  K31,   K32,   K33    }  \
 }
-#endif
-
-#include "quantum.h"