decompressors: make the default XZ_DEC_* config match the selected architecture

Change the defautl XZ_DEC_* config symbol to match the configured
architecture.  It is perfectly legitimate to support multiple XZ BCJ
filters for different architectures (e.g.: to mount foreign squashfs/xz
compressed filesystems), it is however more natural not to select them all
by default, but only the one matching the configured architecture.

Signed-off-by: Florian Fainelli <florian@openwrt.org>
Acked-by: Lasse Collin <lasse.collin@tukaani.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

lib/xz/Kconfig

@@ -10,32 +10,32 @@ if XZ_DEC
 
 config XZ_DEC_X86
 	bool "x86 BCJ filter decoder"
-	default y
+	default y if X86
 	select XZ_DEC_BCJ
 
 config XZ_DEC_POWERPC
 	bool "PowerPC BCJ filter decoder"
-	default y
+	default y if POWERPC
 	select XZ_DEC_BCJ
 
 config XZ_DEC_IA64
 	bool "IA-64 BCJ filter decoder"
-	default y
+	default y if IA64
 	select XZ_DEC_BCJ
 
 config XZ_DEC_ARM
 	bool "ARM BCJ filter decoder"
-	default y
+	default y if ARM
 	select XZ_DEC_BCJ
 
 config XZ_DEC_ARMTHUMB
 	bool "ARM-Thumb BCJ filter decoder"
-	default y
+	default y if (ARM && ARM_THUMB)
 	select XZ_DEC_BCJ
 
 config XZ_DEC_SPARC
 	bool "SPARC BCJ filter decoder"
-	default y
+	default y if SPARC
 	select XZ_DEC_BCJ
 
 endif