media: dt-bindings: media: rockchip-vpu: fix interrupt-names

A test with the command below gives for example this error:

arch/arm64/boot/dts/rockchip/rk3328-evb.dt.yaml: video-codec@ff350000:
interrupts: [[0, 9, 4]] is too short
arch/arm64/boot/dts/rockchip/rk3328-evb.dt.yaml: video-codec@ff350000:
interrupt-names: ['vdpu'] is too short
arch/arm64/boot/dts/rockchip/rk3328-evb.dt.yaml: video-codec@ff350000:
interrupt-names:0: 'vepu' was expected

With the conversion of rockchip-vpu.txt to yaml the correct
'interrupt-names' for rk3328 was not included, so add them now.
Also add 'minItems' to 'interrupts'for the completeness.

make ARCH=arm64 dtbs_check
DT_SCHEMA_FILES=Documentation/devicetree/bindings/media/rockchip-vpu.yaml

Signed-off-by: Johan Jonker <jbx6244@gmail.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>