There is no hard need for this to be a spin lock, as we don't take these
locks in irq context from anywhere. An upcoming patch will add calls to
punit read/write functions from within regions protected by this lock
and those functions need a mutex in turn. As a solution for that convert
the spin lock to be a mutex.
Signed-off-by: NImre Deak <imre.deak@intel.com>
Reviewed-by: NJesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>