g: Add GR_KEYMGR_HKEY_FRR to registers.h
g: Add GR_KEYMGR_HKEY_FRR to registers.h

We'll need this shortly. Adding it now to make testing easier.

BUG=none
BRANCH=none
TEST=make buildall

Signed-off-by: Bill Richardson <129945214b1d548d8e49b6c29c43094f8c78057f@chromium.org>
Change-Id: I6a6636ad330bc17765966cee4962d16850a5d32c
Reviewed-on: https://chromium-review.googlesource.com/344663
Reviewed-by: Dominic Rizzo <a9e5fb9a80871b4edba0a94343af83678d394845@google.com>
Reviewed-by: Mary Ruthven <81380f3403fed74252e92df3ed012a1819ec6296@chromium.org>

coreboot/chrome-ec,coreboot/chrome-ec,coreboot/chrome-ec,coreboot/chrome-ec,coreboot/chrome-ec,coreboot/chrome-ec