xtensa: do not build variants directory

None of arch/xtensa/variants/*/ has Makefile, so 'buildvar' is always
empty.

Perhaps, downstream variant code might be dropped in, but given the
fact that none of upstream variants builds anything in their variant
directory, I doubt this is needed.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Message-Id: <20210811163731.186125-2-masahiroy@kernel.org>
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>

arch/xtensa/Makefile

@@ -55,9 +55,7 @@ KBUILD_CPPFLAGS += $(patsubst %,-I$(srctree)/%include,$(vardirs) $(plfdirs))
 
 KBUILD_DEFCONFIG := iss_defconfig
 
-# Only build variant and/or platform if it includes a Makefile
-
-buildvar := $(shell test -e $(srctree)/arch/xtensa/variants/$(VARIANT)/Makefile && echo arch/xtensa/variants/$(VARIANT)/)
+# Only build platform if it includes a Makefile
 buildplf := $(shell test -e $(srctree)/arch/xtensa/platforms/$(PLATFORM)/Makefile && echo arch/xtensa/platforms/$(PLATFORM)/)
 
 # Find libgcc.a
@@ -66,7 +64,7 @@ LIBGCC := $(shell $(CC) $(KBUILD_CFLAGS) -print-libgcc-file-name)
 
 head-y		:= arch/xtensa/kernel/head.o
 core-y		+= arch/xtensa/kernel/ arch/xtensa/mm/
-core-y		+= $(buildvar) $(buildplf)
+core-y		+= $(buildplf)
 core-y 		+= arch/xtensa/boot/dts/
 
 libs-y		+= arch/xtensa/lib/ $(LIBGCC)