Add greg_t for arm64.

This was already present for the other architectures. I think we skipped
this because glibc seems to have an incorrect definition (int rather than
long), but the kernel has the sane definition (just not in a uapi header).

(cherry picked from commit 8e4d371091e5738346f5c6ad395b8487c2a5ec67)

Bug: 18172268
Change-Id: I22d13fdeb6431ea122dd028a229782dcaf2286b2
1 file changed