m68k: Use IS_ENABLED() instead of checking for built-in or module

Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
diff --git a/arch/m68k/atari/config.c b/arch/m68k/atari/config.c
index cbd5991..97a3c38 100644
--- a/arch/m68k/atari/config.c
+++ b/arch/m68k/atari/config.c
@@ -211,7 +211,7 @@
 	arch_gettimeoffset   = atari_gettimeoffset;
 	mach_reset           = atari_reset;
 	mach_max_dma_address = 0xffffff;
-#if defined(CONFIG_INPUT_M68K_BEEP) || defined(CONFIG_INPUT_M68K_BEEP_MODULE)
+#if IS_ENABLED(CONFIG_INPUT_M68K_BEEP)
 	mach_beep          = atari_mksound;
 #endif
 #ifdef CONFIG_HEARTBEAT