ARM: dts: imx6: remove bogus interrupt-parent from CAAM node

The interrupt-parent property is not needed as it is inherited from
the parent bus and in the case of the CAAM node actively points to
the wrong interrupt controller (GIC instead of GPC). This leads to
the CAAM IRQs not getting unmasked at the GPC level, leaving them
unable to wake the CPU from wait mode, potentially impacting
performance of the CAAM unit when CPUidle is enabled.

Signed-off-by: Lucas Stach <l.stach@pengutronix.de>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>