drm: arm/komeda: Remove IRQ parsing from initial series

The initial series is only introducing the basic components and not
implementing IRQ handling. Remove the left over code that touches
IRQs until the proper implementation is introduced in a later series.

Reviewed-by: James Qian Wang (Arm Technology China) <james.qian.wang@arm.com>
Signed-off-by: Liviu Dudau <liviu.dudau@arm.com>