Make the EN2 pin optional. This is useful for boards,
which have this pin fix wired, for example to ground.
Acked-by: NRob Herring <robh@kernel.org>
Signed-off-by: NGuan Ben <ben.guan@cn.bosch.com>
Signed-off-by: NMark Jonas <mark.jonas@de.bosch.com>
Signed-off-by: NHeiko Schocher <hs@denx.de>
Signed-off-by: NSamuel Ortiz <sameo@linux.intel.com>