arm: Update early-break tests to accept thumb output too.

The tests I recently added for early break fail in thumb mode
because in thumb mode `cbz/cbnz` exist and so the cmp+branch
is fused.  This updates the testcases to accept either output.

gcc/testsuite/ChangeLog:

	* gcc.target/arm/vect-early-break-cbranch.c: Accept thumb output.