powerpc: Add kconfig option to use jump labels for cpu/mmu_has_feature()

Add a kconfig option to control whether we use jump label for the
cpu/mmu_has_feature() checks. Currently this does nothing, but we will
enabled it in the subsequent patches.
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

arch/powerpc/Kconfig.debug

@@ -60,6 +60,15 @@ config CODE_PATCHING_SELFTEST
 	depends on DEBUG_KERNEL
 	default n
 
+config JUMP_LABEL_FEATURE_CHECKS
+	bool "Enable use of jump label for cpu/mmu_has_feature()"
+	depends on JUMP_LABEL
+	default y
+	help
+	  Selecting this options enables use of jump labels for some internal
+	  feature checks. This should generate more optimal code for those
+	  checks.
+
 config FTR_FIXUP_SELFTEST
 	bool "Run self-tests of the feature-fixup code"
 	depends on DEBUG_KERNEL