fbdev: imxfb: Fix style warnings relating to printk()

Resolve the following warning reported by checkpatch:

WARNING: Prefer [subsystem eg: netdev]_err([subsystem]dev, ... then dev_err(dev, ... then pr_err(...  to printk(KERN_ERR ...

This made it necessary to move the 'fbi->pdev = pdev' setting to the
beginning of the driver's probing.

Signed-off-by: Dario Binacchi <dario.binacchi@amarulasolutions.com>
Signed-off-by: Helge Deller <deller@gmx.de>