ARM: dts: odroidxu3: Enable wake alarm of S2MPS11 RTC

The IRQB of S2MPS11 PMIC is wired to XEINT4 (GPX0-4) through pull-up
resistor.

Add interrupt properties and pinctrl configuration to enable RTC wake
alarm of rtc-s5m driver. This also removes a warning:
sec_pmic 4-0066: No interrupt specified, no interrupts

Signed-off-by: Krzysztof Kozlowski <k.kozlowski.k@gmail.com>
Reviewed-by: Javier Martinez Canillas <javier.martinez@collabora.co.uk>
Signed-off-by: Kukjin Kim <kgene@kernel.org>