drm/i915: Fix irq related documentation

drm/i915: Fix irq related documentation

Also update the function names in the documentation.

Closes:
https://lore.kernel.org/intel-gfx/20241001134331.7b4d4ca5@canb.auug.org.au/

Reported-by: Stephen Rothwell <[email protected]>
Fixes: 3de5774cb8c0 ("drm/i915/irq: Rename suspend/resume functions")
Cc: Jonathan Cavitt <[email protected]>
Cc: Andi Shyti <[email protected]>
Reviewed-by: Jonathan Cavitt <[email protected]>
Reviewed-by: Krzysztof Karas <[email protected]>
Reviewed-by: Andi Shyti <[email protected]>
Link: https://patchwork.freedesktop.org/patch/msgid/[email protected]
Signed-off-by: Rodrigo Vivi <[email protected]>