gpio: dwapb: set default handler to be handle_bad_irq()

We switch the default handler to be handle_bad_irq() instead of
handle_level_irq(), though for now apply it later in the code,
to make the difference between IRQ chips more visible.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Tested-by: Serge Semin <fancer.lancer@gmail.com>
Reviewed-by: Serge Semin <fancer.lancer@gmail.com>
Link: https://lore.kernel.org/r/20200415141534.31240-5-andriy.shevchenko@linux.intel.com


Signed-off-by: Linus Walleij <linus.walleij@linaro.org>