selftests: sparc64: Fix to do nothing on non-sparc64

sparc64 test fails with the following errors on non-sparc64 systems. Fix
the Makefile to do nothing on non-sparc64 systems to suppress the errors:

make run_tests
adi-test.c: Assembler messages:
adi-test.c:302: Error: no such instruction: `rd %tick,%r13'
adi-test.c:304: Error: no such instruction: `rd %tick,%rbp'
adi-test.c:190: Error: no such instruction: `rd %tick,%rbp'
adi-test.c:192: Error: no such instruction: `rd %tick,%rdx'
adi-test.c:273: Error: no such instruction: `rd %tick,%rbx'
adi-test.c:276: Error: no such instruction: `rd %tick,%rdx'
adi-test.c:217: Error: no such instruction: `rd %tick,%rbp'
adi-test.c:220: Error: no such instruction: `rd %tick,%rdx'
adi-test.c:79: Error: no such instruction: `rd %tick,%rax'
adi-test.c:79: Error: no such instruction: `rd %tick,%rax'
adi-test.c:79: Error: no such instruction: `rd %tick,%rax'
adi-test.c:79: Error: no such instruction: `rd %tick,%rax'
adi-test.c:246: Error: no such instruction: `rd %tick,%rbp'
adi-test.c:248: Error: no such instruction: `rd %tick,%rdx'
adi-test.c:79: Error: no such instruction: `rd %tick,%rax'
adi-test.c:79: Error: no such instruction: `rd %tick,%rax'
adi-test.c:79: Error: no such instruction: `rd %tick,%rax'
<builtin>: recipe for target 'adi-test' failed
make[1]: *** [adi-test] Error 1
adi: [FAIL]
./drivers_test.sh: 24: ./drivers_test.sh: ./adi-test: not found
../lib.mk:73: recipe for target 'run_tests' failed
make: *** [run_tests] Error 1
Signed-off-by: Shuah Khan (Samsung OSG) <shuah@kernel.org>
Reviewed-by: Tom Hromatka <tom.hromatka@oracle.com>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Shuah Khan (Samsung OSG) <shuah@kernel.org>

tools/testing/selftests/sparc64/Makefile

+uname_M := $(shell uname -m 2>/dev/null || echo not)
+ARCH ?= $(shell echo $(uname_M) | sed -e s/x86_64/x86/)
+
+ifneq ($(ARCH),sparc64)
+nothing:
+.PHONY: all clean run_tests install
+.SILENT:
+else
+
 SUBDIRS := drivers
 
 TEST_PROGS := run.sh
 
+
 .PHONY: all clean
 
 include ../lib.mk
@@ -44,3 +54,4 @@ override define CLEAN
 		make OUTPUT=$$BUILD_TARGET -C $$DIR $@;\
 	done
 endef
+endif