common: silently skip ppc64 tests

ppc64 test execution has been disabled by #5729.
All ppc64 tests are silently skipped as
there is no easy way to disable them.

Signed-off-by: Tomasz Gromadzki <tomasz.gromadzki@intel.com>

src/test/unittest/unittest.sh

@@ -929,6 +929,7 @@ function require_x86_64() {
 # require_ppc64 -- Skip tests if the running platform is not ppc64 or ppc64le
 #
 function require_ppc64() {
+	exit 0
 	require_arch "ppc64" "ppc64le" "ppc64el"
 }