media: mediatek: vcodec: Remove encoder driver get IRQ resource

The "platform_get_resource(pdev, IORESOURCE_IRQ, 0)" is no longer
used after commit a1a2b712("of/platform: Drop static setup of
IRQ resource from DT core"), so just remove the function in
encoder driver to avoid driver probe failed.

Signed-off-by: Irui Wang <irui.wang@mediatek.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>