drm/i915/display: Use display MMIO functions in intel_display_irq.c

drm/i915/display: Use display MMIO functions in intel_display_irq.c

Most of MMIO accesses from intel_display_irq.c are currently done via
uncore_*() functions instead of the display-specific ones, namely
intel_de_*(). Because of that, DMC wakelock ends up being ignored and
some invalid MMIO accesses are performed while display is in dynamic DC
states. Thus, update the display IRQ code to use the intel_de_*() MMIO
functions.

After this change, we are left with some IRQ-specific functions that
still use the unwrapped uncore_*() functions (i.e. gen2_irq_init,
gen3_irq_reset and gen2_assert_iir_is_zero). We will deal with them in
an upcoming change.

Reviewed-by: Jouni Högander <jouni.hogander@intel.com>
Signed-off-by: Gustavo Sousa <gustavo.sousa@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20250113204306.112266-2-gustavo.sousa@intel.com