Use the irq_chip bus_sync_unlock method to update hardware registers
instead of scheduling work from the mask/unmask methods. This simplifies
a bit the driver and make it more uniform with the other GPIO IRQ
drivers.
Signed-off-by: Octavian Purdila <octavian.purdila@intel.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>