kbuild: clean up stale file removal

More than one year has passed since the copied *.[cS] files were
removed from arch/*/boot/compressed/.

Signed-off-by: Masahiro Yamada <[e-mail]>

arch/sh/boot/compressed/Makefile

···
 OBJECTS := head_32.o misc.o cache.o piggy.o \
            ashiftrt.o ashldi3.o ashrsi3.o ashlsi3.o lshrsi3.o
 
-# These were previously generated files. When you are building the kernel
-# with O=, make sure to remove the stale files in the output tree. Otherwise,
-# the build system wrongly compiles the stale ones.
-ifdef building_out_of_srctree
-$(shell rm -f $(addprefix $(obj)/, ashiftrt.S ashldi3.c ashrsi3.S ashlsi3.S lshrsi3.S))
-endif
-
 targets := vmlinux vmlinux.bin vmlinux.bin.gz vmlinux.bin.bz2 \
            vmlinux.bin.lzma vmlinux.bin.xz vmlinux.bin.lzo $(OBJECTS)
 

scripts/remove-stale-files

···
 # then will be really dead and removed from the code base entirely.
 
 rm -f arch/powerpc/purgatory/kexec-purgatory.c
-
-# These were previously generated source files. When you are building the kernel
-# with O=, make sure to remove the stale files in the output tree. Otherwise,
-# the build system wrongly compiles the stale ones.
-if [ -n "${building_out_of_srctree}" ]; then
-	for f in fdt_rw.c fdt_ro.c fdt_wip.c fdt.c ashldi3.S bswapsdi2.S font.c lib1funcs.S hyp-stub.S
-	do
-		rm -f arch/arm/boot/compressed/${f}
-	done
-
-	for f in uart-ath79.c ashldi3.c bswapdi.c bswapsi.c
-	do
-		rm -f arch/mips/boot/compressed/${f}
-	done
-
-	for f in firmware.c real2.S
-	do
-		rm -f arch/parisc/boot/compressed/${f}
-	done
-fi
-
 rm -f arch/riscv/purgatory/kexec-purgatory.c
+rm -f arch/x86/purgatory/kexec-purgatory.c
 
 rm -f scripts/extract-cert
-
-rm -f arch/x86/purgatory/kexec-purgatory.c
 
 rm -f scripts/kconfig/[gmnq]conf-cfg