mx6: mx6qsabrelite/nitrogen6x: Remove incorrect setting of gpio CS signal

mx6: mx6qsabrelite/nitrogen6x: Remove incorrect setting of gpio CS signal

The number of gpio signal is packed inside CONFIG_SF_DEFAULT_CS macro
(shifted and or'ed with chip select), so it's incorrect to pass
that macro directly as an argument to gpio_direction_output() call.

Also, SPI driver sets the direction and initial value of a gpio,
used as a chip select signal, before any actual activity happens
on the bus.

So, it is safe to just remove the gpio_direction_output call,
that works incorrectly, thus making no effect, anyway.

Signed-off-by: Andrew Gabbasov <andrew_gabbasov@mentor.com>
Tested-by: Robert Winkler <robert.winkler@boundarydevices.com>
Acked-by: Dirk Behme <dirk.behme@de.bosch.com>