hwspinlock: qcom: Add support for mmio usage to sfpb-mutex

Allow sfpb-mutex to use mmio in addition to syscon.

Signed-off-by: Christian Marangi <ansuelsmth@gmail.com>
Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Link: https://lore.kernel.org/r/20220707102040.1859-1-ansuelsmth@gmail.com