arm64: dts: imx8mn: correct interrupt flags

GPIO_ACTIVE_x flags are not correct in the context of interrupt flags.
These are simple defines so they could be used in DTS but they will not
have the same meaning:
1. GPIO_ACTIVE_HIGH = 0 = IRQ_TYPE_NONE
2. GPIO_ACTIVE_LOW  = 1 = IRQ_TYPE_EDGE_RISING

Correct the interrupt flags, assuming the author of the code wanted same
logical behavior behind the name "ACTIVE_xxx", this is:
  ACTIVE_LOW  => IRQ_TYPE_LEVEL_LOW

For level low interrupts, enable also internal pull up.  It is
required at least on imx8mm-evk, according to schematics.

Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Acked-By: Tim Harvey <tharvey@gateworks.com>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>