MIPS: Use the new "ZC" constraint for MIPS R6
MIPS: Use the new "ZC" constraint for MIPS R6

GCC versions supporting MIPS R6 use the ZC constraint to enforce a
9-bit offset for MIPS R6. We will use that for all MIPS R6 LL/SC
instructions.

Cc: Matthew Fortune <36abb7af599a47bad00c7d344bf309af35eee58c@imgtec.com>
Signed-off-by: Markos Chandras <5cdbcb0e11d2b5ebc39222958c54a1c6329d0c9d@imgtec.com>

KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs