fix compile error introduced by LoongArch commit

LoongArch inclusion
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I6MV9N

--------------------------------

when compile kernel using the following steps:

make allmodconfig ARCH=x86_64 CROSS_COMPILE=x86_64-linux-gnu-
make oldconfig ARCH=x86_64 CROSS_COMPILE=x86_64-linux-gnu-
make -j64 ARCH=x86_64 CROSS_COMPILE=x86_64-linux-gnu-

we get error:

  DESCEND  objtool
  HOSTCC  scripts/sorttable
In file included from scripts/sorttable.c:195:
scripts/sorttable.h:89:10: fatal error: asm/orc_types.h: No such file or directory
   89 | #include <asm/orc_types.h>
      |          ^~~~~~~~~~~~~~~~~
compilation terminated.
make[1]: *** [scripts/Makefile.host:95: scripts/sorttable] Error 1
make: *** [Makefile:1215: scripts] Error 2
make: *** Waiting for unfinished jobs....

the reason is ARCH a command-line variable,the normal assignment is
ignored.So split loongarch architecture from others.

Fixes: 4efd0de6 ("tools/perf: Add basic support for LoongArch")
Signed-off-by: NHongchen Zhang <zhanghongchen@loongson.cn>
Signed-off-by: NZheng Zengkai <zhengzengkai@huawei.com>
Signed-off-by: NJialin Zhang <zhangjialin11@huawei.com>

scripts/Makefile

@@ -24,20 +24,19 @@ HOSTCFLAGS_extract-cert.o = $(CRYPTO_CFLAGS)
 HOSTLDLIBS_extract-cert = $(CRYPTO_LIBS)
 
 ifdef CONFIG_UNWINDER_ORC
-# Additional ARCH settings for x86
+ifneq ($(filter loongarch loongarch64, $(ARCH)),)
+HOSTCFLAGS_sorttable.o += -I$(srctree)/tools/arch/loongarch/include
+HOSTCFLAGS_sorttable.o += -DUNWINDER_ORC_ENABLED
+HOSTLDLIBS_sorttable = -lpthread
+else
 ifeq ($(ARCH),x86_64)
 ARCH := x86
 endif
-
-# Additional ARCH settings for loongarch
-ifeq ($(ARCH),loongarch64)
-ARCH := loongarch
-endif
-
-HOSTCFLAGS_sorttable.o += -I$(srctree)/tools/arch/$(ARCH)/include
+HOSTCFLAGS_sorttable.o += -I$(srctree)/tools/arch/x86/include
 HOSTCFLAGS_sorttable.o += -DUNWINDER_ORC_ENABLED
 HOSTLDLIBS_sorttable = -lpthread
 endif
+endif
 
 # The following programs are only built on demand
 hostprogs += unifdef