Revert "ANDROID: KVM: arm64: Use enum instead of helper for fp state"

This reverts commit 26d24625, which
didn't introduce any functional change. This is reverted because
backported commits rely on the helpers that the commit has removed.
Reverting it makes it easier and cleaner to apply the backports.

No functional change intended.

Bug: 411040189
Change-Id: Ie29ece274cfc970cf116f8781b841b9ac2c5aa56
Signed-off-by: Fuad Tabba <tabba@google.com>