remoteproc: fix checkpatch errors in remoteproc code

This patch fixes relevant checkpatch errors and warnings
in the remoteproc source files.

Signed-off-by: Suman Anna <s-anna@ti.com>
[drop 80-char-lines checkpatch fixes and update commit log accordingly]
Signed-off-by: Ohad Ben-Cohen <ohad@wizery.com>