powerpc/build: Remove -pipe from compilation flags

x86 removed -pipe in commit 437e88ab ("x86/build: Remove -pipe from
KBUILD_CFLAGS") and the newer arm64 and riscv seem to have never used it,
so that seems to be the way the world's going.

Compile performance building defconfig on a POWER10 PowerNV system
was in the noise after 10 builds each. No point in adding options unless
they help something, so remove it.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20230606064830.184083-1-npiggin@gmail.com

arch/powerpc/Makefile

@@ -166,7 +166,7 @@ asinstr := $(call as-instr,lis 9$(comma)foo@high,-DHAVE_AS_ATHIGH=1)
 KBUILD_CPPFLAGS	+= -I $(srctree)/arch/$(ARCH) $(asinstr)
 KBUILD_AFLAGS	+= $(AFLAGS-y)
 KBUILD_CFLAGS	+= $(call cc-option,-msoft-float)
-KBUILD_CFLAGS	+= -pipe $(CFLAGS-y)
+KBUILD_CFLAGS	+= $(CFLAGS-y)
 CPP		= $(CC) -E $(KBUILD_CFLAGS)
 
 CHECKFLAGS	+= -m$(BITS) -D__powerpc__ -D__powerpc$(BITS)__

arch/powerpc/boot/Makefile

@@ -71,7 +71,7 @@ endif
 BOOTCPPFLAGS	:= -nostdinc $(LINUXINCLUDE)
 BOOTCPPFLAGS	+= -isystem $(shell $(BOOTCC) -print-file-name=include)
 
-BOOTCFLAGS	:= -pipe $(BOOTTARGETFLAGS) \
+BOOTCFLAGS	:= $(BOOTTARGETFLAGS) \
 		   -Wall -Wundef -Wstrict-prototypes -Wno-trigraphs \
 		   -fno-strict-aliasing -O2 \
 		   -msoft-float -mno-altivec -mno-vsx \
@@ -81,7 +81,7 @@ BOOTCFLAGS	:= -pipe $(BOOTTARGETFLAGS) \
 		   $(call cc-option,-mno-spe) $(call cc-option,-mspe=no) \
 		   -fomit-frame-pointer -fno-builtin -fPIC
 
-BOOTAFLAGS	:= -pipe $(BOOTTARGETFLAGS) -D__ASSEMBLY__
+BOOTAFLAGS	:= $(BOOTTARGETFLAGS) -D__ASSEMBLY__
 
 BOOTARFLAGS	:= -crD