ARM: dts: imx6: phytec: fix RTC interrupt level

ARM: dts: imx6: phytec: fix RTC interrupt level

[ Upstream commit 762b700982a1e0f562184363f19860c3b9bdd0bf ]

RTC interrupt level should be set to "LOW". This was revealed by the
introduction of commit:

  f181987ef477 ("rtc: m41t80: use IRQ flags obtained from fwnode")

which changed the way IRQ type is obtained.

Signed-off-by: Andrej Picej <andrej.picej@norik.com>
Reviewed-by: Stefan Riedmüller <s.riedmueller@phytec.de>
Fixes: 800d595151bb ("ARM: dts: imx6: Add initial support for phyBOARD-Mira")
Signed-off-by: Shawn Guo <shawnguo@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>