fb: add a usage counter to prevent double enable/disable ...

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

rework device parameters ...

Change device parameters so that the memory management is in generic
code. This also removes the need of storing statically initialized
parameters as they are stored in a struct list_head for each device.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

Add framebuffer support ...

This patch adds framebuffer support and a driver for i.MX[12]
framebuffer devices.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>