imx6: kernel: backport upstream fix for IMX6DL 800MHz speed grade

A previous backported patch that adds freq/voltage operating points for the
IMX6DL processor can cause hang/crash (general instability) on IMX6DL
processors in the industrial/automative speed grades as they don't support
1GHz operation.

This adds another backported patch from mainline that uses IMX6 fuse settings
to properly remove invalid operating points for the particular CPU grade used.

Signed-off-by: Tim Harvey <tharvey@gateworks.com>

SVN-Revision: 42294