selftests/bpf: Enable kptr_xchg_inline test for arm64

Now arm64 bpf jit has enable bpf_jit_supports_ptr_xchg(), so enable
the test for arm64 as well.
Signed-off-by: Hou Tao <houtao1@huawei.com>
Link: https://lore.kernel.org/r/20240119102529.99581-3-houtao@huaweicloud.comSigned-off-by: Alexei Starovoitov <ast@kernel.org>

tools/testing/selftests/bpf/prog_tests/kptr_xchg_inline.c

@@ -13,7 +13,7 @@ void test_kptr_xchg_inline(void)
 	unsigned int cnt;
 	int err;
 
-#if !defined(__x86_64__)
+#if !(defined(__x86_64__) || defined(__aarch64__))
 	test__skip();
 	return;
 #endif