media: staging: media: ipu3-imgu: Request specific firmware binary

Primarily request a specific revision of the IPU3 firmware that the driver
is known to work with,
irci_irci_ecr-master_20161208_0213_20170112_1500.bin. Some distros only
ship this while others provide a symlink called ipu3-fw.bin, which the
driver only requested previously.

Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>