irq_set_type() should not implicitly unmask the IRQ.

All accesses to the interrupt configuration register are moved to a new
helper tqmx86_gpio_irq_config(). We also introduce the new rule that
accessing irq_type must happen while locked, which will become
significant for fixing EDGE_BOTH handling.

Fixes: b868db94 ("gpio: tqmx86: Add GPIO from for this IO controller")
Signed-off-by: Matthias Schiffer <matthias.schiffer@ew.tq-group.com>
Link: https://lore.kernel.org/r/6aa4f207f77cb58ef64ffb947e91949b0f753ccd.1717063994.git.matthias.schiffer@ew.tq-group.comSigned-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>