Add HWCAP2_MOPS from Linux 6.5 to AArch64 bits/hwcap.h

Linux 6.5 adds a new AArch64 HWCAP2 value, HWCAP2_MOPS.  Add it to
glibc's bits/hwcap.h.

Tested with build-many-glibcs.py for aarch64-linux-gnu.