registers and use it in the ARMv7 CPU functions.
The sysreg.h file has been checked by hand, however it may contain errors
with the comments on when a register was first introduced. The ARMv7 cpu
functions have been checked by compiling both the previous and this version
and comparing the md5 of the object files.
Submitted by: Svatopluk Kraus <onwahe at gmail.com>
Submitted by: Michal Meloun <meloun at miracle.cz>
Reviewed by: ian, rpaulo
Differential Revision: https://reviews.freebsd.org/D795
