Revert "Kconfig: allow CC_OPTIMIZE_FOR_PERFORMANCE_O3 on all arches"

This reverts commit 19f6835.

	modified:   arch/arc/Makefile
	modified:   init/Kconfig

arch/arc/Makefile

@@ -44,6 +44,14 @@ endif
 cfi := $(call as-instr,.cfi_startproc\n.cfi_endproc,-DARC_DW2_UNWIND_AS_CFI)
 cflags-$(CONFIG_ARC_DW2_UNWIND)		+= -fasynchronous-unwind-tables $(cfi)
 
+ifndef CONFIG_CC_OPTIMIZE_FOR_SIZE
+# Generic build system uses -O2, we want -O3
+# Note: No need to add to cflags-y as that happens anyways
+#
+# Disable the false maybe-uninitialized warings gcc spits out at -O3
+ARCH_CFLAGS += -O3 $(call cc-disable-warning,maybe-uninitialized,)
+endif
+
 # small data is default for elf32 tool-chain. If not usable, disable it
 # This also allows repurposing GP as scratch reg to gcc reg allocator
 disable_small_data := y

init/Kconfig

@@ -1154,20 +1154,14 @@ choice
 	default CC_OPTIMIZE_FOR_PERFORMANCE
 
 config CC_OPTIMIZE_FOR_PERFORMANCE
-	bool "Optimize for performance (-O2)"
+	bool "Optimize for performance"
 	help
 	  This is the default optimization level for the kernel, building
 	  with the "-O2" compiler flag for best performance and most
 	  helpful compile-time warnings.
 
-config CC_OPTIMIZE_FOR_PERFORMANCE_O3
-	bool "Optimize more for performance (-O3)"
-	help
-	  Choosing this option will pass "-O3" to your compiler to optimize
-	  the kernel yet more for performance.
-
 config CC_OPTIMIZE_FOR_SIZE
-	bool "Optimize for size (-Os)"
+	bool "Optimize for size"
 	help
 	  Enabling this option will pass "-Os" instead of "-O2" to
 	  your compiler resulting in a smaller kernel.