arch/sparc: Fix FPU register corruption with AES crypto test on M7

arch/sparc: Fix FPU register corruption with AES crypto test on M7

We noticed crypto key corruption while running AES crypto tests
with M7 memcpy changes. Investigating further, we found that this
was the same problem reported previously with NG4memcpy. The commit
f4da3628dc7c ("sparc64: Fix FPU register corruption with AES crypto
offload") fixes the problem. Ported these changes to M7memcpy.

Orabug: 25265878

Signed-off-by: Babu Moger <babu.moger@oracle.com>
Tested-by: Stanislav Kholmanskikh <stanislav.kholmanskikh@oracle.com>
Signed-off-by: Allen Pais <allen.pais@oracle.com>