Revert "powerpc/xmon: Relax frame size for clang"

This reverts commit 9c87156.

I have not been able to reproduce the reported -Wframe-larger-than=
warning (or disassembly) with clang-11 or clang-18.

I don't know precisely when this was fixed in llvm, but it may be time
to revert this.

Closes: ClangBuiltLinux#252
Signed-off-by: Nick Desaulniers <[email protected]>

Author: nickdesaulniers

arch/powerpc/xmon/Makefile

@@ -10,12 +10,6 @@ KCSAN_SANITIZE := n
 # Disable ftrace for the entire directory
 ccflags-remove-$(CONFIG_FUNCTION_TRACER) += $(CC_FLAGS_FTRACE)
 
-ifdef CONFIG_CC_IS_CLANG
-# clang stores addresses on the stack causing the frame size to blow
-# out. See https://github.com/ClangBuiltLinux/linux/issues/252
-KBUILD_CFLAGS += -Wframe-larger-than=4096
-endif
-
 ccflags-$(CONFIG_PPC64) := $(NO_MINIMAL_TOC)
 
 obj-y			+= xmon.o nonstdio.o spr_access.o xmon_bpts.o