BugLink: https://bugs.launchpad.net/bugs/1822271

This reverts commit 7212e37cbdf99f48e4a6c689a42f4bda1ae69001.

Hedi Berriche <hedi.berriche@hpe.com> notes:

> In 4.4-stable efi_runtime_lock as defined in drivers/firmware/efi/runtime-wrappers.c
> is a spinlock (given it predates commit dce48e35) and commit
>
>         f331e766 x86/platform/UV: Use efi_runtime_lock to serialise BIOS calls
>
> which 7212e37cbdf9 is a backport of, needs it to be a semaphore.
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Stefan Bader <stefan.bader@canonical.com>
Acked-by: Juerg Haefliger <juerg.haefliger@canonical.com>
Signed-off-by: Kleber Sacilotto de Souza <kleber.souza@canonical.com>