pinctrl: sunxi: sun50i-h5 use platform_irq_count

platform_irq_count() is the more generic way (independent of
device trees) to determine the count of available interrupts. So
use this instead.

As platform_irq_count() might return an error code (which
of_irq_count doesn't) some additional handling is necessary.

Signed-off-by: Peng Fan <peng.fan@nxp.com>
Link: https://lore.kernel.org/r/1576672860-14420-2-git-send-email-peng.fan@nxp.com


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