powerpc: Add -Werror at arch/powerpc level

Back when I added -Werror in commit ba55bd74 ("powerpc: Add
configurable -Werror for arch/powerpc") I did it by adding it to most
of the arch Makefiles.

At the time we excluded math-emu, because apparently it didn't build
cleanly. But that seems to have been fixed somewhere in the interim.

So move the -Werror addition to the top-level of the arch, this saves
us from repeating it in every Makefile and means we won't forget to
add it to any new sub-dirs.
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

arch/powerpc/Kbuild

+subdir-ccflags-$(CONFIG_PPC_WERROR) := -Werror
+
 obj-y += kernel/
 obj-y += mm/
 obj-y += lib/

arch/powerpc/kernel/Makefile

@@ -8,8 +8,6 @@ CFLAGS_ptrace.o		+= -DUTS_MACHINE='"$(UTS_MACHINE)"'
 # Disable clang warning for using setjmp without setjmp.h header
 CFLAGS_crash.o		+= $(call cc-disable-warning, builtin-requires-header)
 
-subdir-ccflags-$(CONFIG_PPC_WERROR) := -Werror
-
 ifdef CONFIG_PPC64
 CFLAGS_prom_init.o	+= $(NO_MINIMAL_TOC)
 endif

arch/powerpc/kernel/trace/Makefile

@@ -3,8 +3,6 @@
 # Makefile for the powerpc trace subsystem
 #
 
-subdir-ccflags-$(CONFIG_PPC_WERROR)	:= -Werror
-
 ifdef CONFIG_FUNCTION_TRACER
 # do not trace tracer code
 CFLAGS_REMOVE_ftrace.o = $(CC_FLAGS_FTRACE)

arch/powerpc/kvm/Makefile

@@ -3,8 +3,6 @@
 # Makefile for Kernel-based Virtual Machine module
 #
 
-subdir-ccflags-$(CONFIG_PPC_WERROR) := -Werror
-
 ccflags-y := -Ivirt/kvm -Iarch/powerpc/kvm
 KVM := ../../../virt/kvm
 

arch/powerpc/lib/Makefile

@@ -3,8 +3,6 @@
 # Makefile for ppc-specific library files..
 #
 
-subdir-ccflags-$(CONFIG_PPC_WERROR) := -Werror
-
 ccflags-$(CONFIG_PPC64)	:= $(NO_MINIMAL_TOC)
 
 CFLAGS_REMOVE_code-patching.o = $(CC_FLAGS_FTRACE)

arch/powerpc/mm/Makefile

@@ -3,8 +3,6 @@
 # Makefile for the linux ppc-specific parts of the memory manager.
 #
 
-subdir-ccflags-$(CONFIG_PPC_WERROR) := -Werror
-
 ccflags-$(CONFIG_PPC64)	:= $(NO_MINIMAL_TOC)
 
 CFLAGS_REMOVE_slb.o = $(CC_FLAGS_FTRACE)

arch/powerpc/oprofile/Makefile

 # SPDX-License-Identifier: GPL-2.0
-subdir-ccflags-$(CONFIG_PPC_WERROR) := -Werror
 
 ccflags-$(CONFIG_PPC64)	:= $(NO_MINIMAL_TOC)
 

arch/powerpc/perf/Makefile

 # SPDX-License-Identifier: GPL-2.0
-subdir-ccflags-$(CONFIG_PPC_WERROR) := -Werror
 
 obj-$(CONFIG_PERF_EVENTS)	+= callchain.o perf_regs.o
 

arch/powerpc/platforms/Makefile

 # SPDX-License-Identifier: GPL-2.0
 
-subdir-ccflags-$(CONFIG_PPC_WERROR) := -Werror
-
 obj-$(CONFIG_FSL_ULI1575)	+= fsl_uli1575.o
 
 obj-$(CONFIG_PPC_PMAC)		+= powermac/

arch/powerpc/sysdev/Makefile

 # SPDX-License-Identifier: GPL-2.0
-subdir-ccflags-$(CONFIG_PPC_WERROR) := -Werror
 
 ccflags-$(CONFIG_PPC64)		:= $(NO_MINIMAL_TOC)
 
@@ -56,8 +55,6 @@ obj-$(CONFIG_PPC_SCOM)		+= scom.o
 
 obj-$(CONFIG_PPC_EARLY_DEBUG_MEMCONS)	+= udbg_memcons.o
 
-subdir-ccflags-$(CONFIG_PPC_WERROR) := -Werror
-
 obj-$(CONFIG_PPC_XICS)		+= xics/
 obj-$(CONFIG_PPC_XIVE)		+= xive/
 

arch/powerpc/sysdev/xics/Makefile

 # SPDX-License-Identifier: GPL-2.0
-subdir-ccflags-$(CONFIG_PPC_WERROR) := -Werror
 
 obj-y				+= xics-common.o
 obj-$(CONFIG_PPC_ICP_NATIVE)	+= icp-native.o

arch/powerpc/sysdev/xive/Makefile

-subdir-ccflags-$(CONFIG_PPC_WERROR) := -Werror
 
 obj-y				+= common.o
 obj-$(CONFIG_PPC_XIVE_NATIVE)	+= native.o

arch/powerpc/xmon/Makefile

@@ -4,8 +4,6 @@
 # Disable clang warning for using setjmp without setjmp.h header
 subdir-ccflags-y := $(call cc-disable-warning, builtin-requires-header)
 
-subdir-ccflags-$(CONFIG_PPC_WERROR) += -Werror
-
 GCOV_PROFILE := n
 UBSAN_SANITIZE := n