ANDROID: Partially Revert "ANDROID: KVM: arm64: Allow tweaking HFGWTR_EL2 from modules"

This is a partial revert of commit 085255b9 in order to fix booting
this kernel on devices that don't support FEAT_FGT due to direct
accesses of HFGWTR_EL2 being UNDEFINED. We are retaining the KMI part of
the commit until the next KMI breakage window.

Bug: 282917063
Change-Id: I6c156ef40a5584dc41e4d9d09c80736e30348802
Signed-off-by: Will McVicker <willmcvicker@google.com>