Interrupts do not have to be always GPIO based so instead of expecting
"int-gpios" property and converting the GPIO to an interrupt, just
accept any interrupt via generic "interrupts" property.

Keep support for old "int-gpios" for backward compatibility.
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Reviewed-by: Vijai Kumar K <vijaikumar.kanagarajan@gmail.com>
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>