drivers/gpio/gpiolib: Add support for removing registered consumer lookup table

drivers/gpio/gpiolib: Add support for removing registered consumer lookup table

In case we unload and load a driver module again that is registering a
lookup table, without this it will result in multiple entries. Provide
an option to remove the lookup table on driver unload

v2: Ccing maintainers

Cc: Samuel Ortiz <sameo@linux.intel.com>
Cc: Linus Walleij <linus.walleij@linaro.org>
Cc: Alexandre Courbot <gnurou@gmail.com>
Cc: Thierry Reding <thierry.reding@gmail.com>
Signed-off-by: Shobhit Kumar <shobhit.kumar@intel.com>