staging: sm7xx: merge hardware information in smtcfb_info struct

With this patch smtcfb_info becomes the main structure to reach/handle
state. fb_info struct links this struct via its private data field.

This change improves encapsulation in functions. It reduces the number
of arguments used in signatures too.

Tested with SM712

Signed-off-by: Javier M. Mellid <jmunhoz@igalia.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>