generic: make optimized inlining arch-opt-in

Stephen Rothwell reported that linux-next did not build on powerpc64.

make optimized inlining dependent on architecture opt-in.

Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 4d350b5..3b6ff3b 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -142,6 +142,9 @@
 config ARCH_SUPPORTS_AOUT
 	def_bool y
 
+config ARCH_SUPPORTS_OPTIMIZED_INLINING
+	def_bool y
+
 # Use the generic interrupt handling code in kernel/irq/:
 config GENERIC_HARDIRQS
 	bool