default to ELF for MMU architectures, unbreak bootup with missing ELF kernel support

target/config/Config.in.binfmt

@@ -3,19 +3,10 @@
 
 choice
 prompt "Binary Format"
-depends on ADK_TARGET_ARCH_ARM \
-	|| ADK_TARGET_ARCH_BFIN \
-	|| ADK_TARGET_ARCH_C6X \
-	|| ADK_TARGET_ARCH_FRV \
-	|| ADK_TARGET_ARCH_H8300 \
-	|| ADK_TARGET_ARCH_LM32 \
-	|| ADK_TARGET_ARCH_M68K \
-	|| ADK_TARGET_ARCH_SH \
-	|| ADK_TARGET_ARCH_XTENSA
 
 config ADK_TARGET_BINFMT_ELF
 	bool "ELF"
-	depends on (ADK_TARGET_ARCH_ARM || ADK_TARGET_ARCH_M68K || ADK_TARGET_ARCH_SH || ADK_TARGET_ARCH_XTENSA) && ADK_TARGET_WITH_MMU
+	depends on ADK_TARGET_WITH_MMU
 
 config ADK_TARGET_BINFMT_FLAT
 	bool "FLAT"