testsuite: Add CRIS to targets not xfailing gcc.dg/attr-alloc_size-11.c:50,51

Reacting to a long-standing XPASS for CRIS.  Maybe better do
as https://gcc.gnu.org/PR79356#c11 suggests: xfail it for
x86 only ...except I see m68k also does not xpass.

testsuite:
	PR testsuite/79356
	* gcc.dg/attr-alloc_size-11.c: Add CRIS to the list
	of targets excluding xfail on lines 50 and 51.