media: MAINTAINERS: add atmel-isc-media.h file to ATMEL ISC driver

Add new file include/linux/atmel-isc-media.h to ATMEL ISC entry.

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>