staging: gdm72xx: Whitespace fixes to conform to coding standards

Fixes the following checkpatch.pl issues:

WARNING: unnecessary whitespace before a quoted newline
CHECK: Alignment should match open parenthesis
CHECK: No space is necessary after a cast

Also some additional, whitespace related, readability issues.

Signed-off-by: Michalis Pappas <mpappas@fastmail.fm>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>