Add HWCAP2_AFP, HWCAP2_RPRES from Linux 5.17 to AArch64 bits/hwcap.h

Add the new HWCAP2_AFP and HWCAP2_RPRES constants from Linux 5.17.
Tested with build-many-glibcs.py for aarch64-linux-gnu.

(cherry picked from commit 866c5991)