gpio: dwapb: Remove unneeded has_irq member in struct dwapb_port_property

gpio: dwapb: Remove unneeded has_irq member in struct dwapb_port_property

has_irq member of struct dwapb_port_property is used only in one place,
so, make it local test instead and remove from the structure.
This local test is using memchr_inv() which is quite efficient in comparison
to the original loop and possible little overhead can be neglected.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Tested-by: Serge Semin <fancer.lancer@gmail.com>
Acked-by: Lee Jones <lee.jones@linaro.org>
Acked-by: Serge Semin <fancer.lancer@gmail.com>
Link: https://lore.kernel.org/r/20200519131233.59032-4-andriy.shevchenko@linux.intel.com
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>