[media] media: mx2_camera: Fix clock handling for i.MX27

On i.MX27 two clocks are required: emma-ipg and emma-ahb. The ahb clock
has to be requested using both a device and a connection ID.

Signed-off-by: Javier Martin <javier.martin@vista-silicon.com>
[g.liakhovetski@gmx.de: rebase to the current media tree]
Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>