Staging: sm750fb: Replace spaces with tabs at the start of lines

Replace spaces at the start of lines with tabs to rectify
the following warning:
WARNING: please, no spaces at the start of a line

Signed-off-by: Isaac Assegai <isaac.a.travers@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>