gpio: introduce a header for symbols shared by suppliers and consumers

gpio: introduce a header for symbols shared by suppliers and consumers

GPIO_LINE_DIRECTION_IN/OUT definitions are used both in supplier (GPIO
controller drivers) as well as consumer code. In order to not force the
consumers to include gpio/driver.h or - even worse - to redefine these
values, create a new header file - gpio/defs.h - and move them over
there. Include this header from both gpio/consumer.h and gpio/driver.h.

Reviewed-by: Linus Walleij <linusw@kernel.org>
Suggested-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://patch.msgid.link/20260223172006.204268-1-bartosz.golaszewski@oss.qualcomm.com
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@oss.qualcomm.com>