staging: nvec: Introduce nvec_gpio_set_value()

Introduce nvec_gpio_set_value(), which works like
gpio_set_value(), but also creates a debugging
message, if that's enabled.

Signed-off-by: Julian Andres Klode <jak@jak-linux.org>
Acked-by: Marc Dietrich <marvin24@gmx.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>