media: atmel: atmel-isc: add microchip-xisc driver

Add driver for the extended variant of the isc, the microchip XISC
present on sama7g5 product.

[hverkuil: drop MODULE_SUPPORTED_DEVICE, no longer exists]
[hverkuil: made isc_sama7g5_config_csc et al static]
[hverkuil: made sama7g5_controller_formats et al static]

Signed-off-by: Eugen Hristev <eugen.hristev@microchip.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>