FROMLIST: KVM: arm64: Introduce wrappers for host and hyp spin lock accessors

In preparation for adding additional locked sections for manipulating
page-tables at EL2, introduce some simple wrappers around the host and
hypervisor locks so that it's a bit easier to read and bit more difficult
to take the wrong lock (or even take them in the wrong order).

Signed-off-by: Will Deacon <will@kernel.org>
Signed-off-by: Quentin Perret <qperret@google.com>
Link: https://lore.kernel.org/r/20211201170411.1561936-11-qperret@google.com
Bug: 209599700
Change-Id: If6a1baf1dc099894c3445d6b6fec4dd3a46164a9