testsuite: Skip powerpc tests on AIX.

AIX does not support -mstrict-align.

pr109566.c had skip directive in wrong order for DejaGNU.

	* gcc.target/powerpc/pr100106-sa.c: Skip on AIX.
	* gcc.target/powerpc/pr109566.c: Skip on AIX.

Signed-off-by: David Edelsohn <dje.gcc@gmail.com>