selftests/sgx: Skip non X86_64 platform

JIRA: https://issues.redhat.com/browse/RHEL-22826
Upstream Status: merged into the linux.git

commit 981cf56
Author: Zhao Mengmeng <zhaomengmeng@kylinos.cn>
Date:   Tue Dec 5 21:56:05 2023 -0500

    selftests/sgx: Skip non X86_64 platform

    When building whole selftests on arm64, rsync gives an erorr about sgx:

    rsync: [sender] link_stat "/root/linux-next/tools/testing/selftests/sgx/test_encl.elf" failed: No such file or directory (2)
    rsync error: some files/attrs were not transferred (see previous errors) (code 23) at main.c(1327) [sender=3.2.5]

    The root casue is sgx only used on X86_64, and shall be skipped on other
    platforms.

    Fix this by moving TEST_CUSTOM_PROGS and TEST_FILES inside the if check,
    then the build result will be "Skipping non-existent dir: sgx".

    Fixes: 2adcba7 ("selftests/x86: Add a selftest for SGX")
    Signed-off-by: Zhao Mengmeng <zhaomengmeng@kylinos.cn>
    Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
    Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org>
    Link: https://lore.kernel.org/all/20231206025605.3965302-1-zhaomzhao%40126.com

Signed-off-by: Vladis Dronov <vdronov@redhat.com>

Author: nefigtut

tools/testing/selftests/sgx/Makefile

@@ -18,10 +18,10 @@ ENCL_CFLAGS += -Wall -Werror -static-pie -nostdlib -ffreestanding -fPIE \
 	       -fno-stack-protector -mrdrnd $(INCLUDES)
 ENCL_LDFLAGS := -Wl,-T,test_encl.lds,--build-id=none
 
+ifeq ($(CAN_BUILD_X86_64), 1)
 TEST_CUSTOM_PROGS := $(OUTPUT)/test_sgx
 TEST_FILES := $(OUTPUT)/test_encl.elf
 
-ifeq ($(CAN_BUILD_X86_64), 1)
 all: $(TEST_CUSTOM_PROGS) $(OUTPUT)/test_encl.elf
 endif