gpu: drm: drivers: Convert printk(KERN_<LEVEL> to pr_<level>

Use a more common logging style.

Miscellanea:

o Coalesce formats and realign arguments
o Neaten a few macros now using pr_<level>

Signed-off-by: Joe Perches <joe@perches.com>
Acked-by: Rob Clark <robdclark@gmail.com>
Acked-by: Sinclair Yeh <syeh@vmware.com>
Acked-by: Patrik Jakobsson <patrik.r.jakobsson@gmail.com>
Acked-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/76355db47b31668bb64d996865ceee53bd66b11f.1488285953.git.joe@perches.com