ARM: ep93xx: Convert to use descriptors for GPIO LEDs

ARM: ep93xx: Convert to use descriptors for GPIO LEDs

This converts the EP93xx to use GPIO descriptors for the
LEDs.

Cc: Nikita Shubin <nikita.shubin@maquefel.me>
Cc: Alexander Sverdlin <alexander.sverdlin@gmail.com>
Cc: Hartley Sweeten <hsweeten@visionengravers.com>
Cc: Lukasz Majewski <lukma@denx.de>
Tested-by: Alexander Sverdlin <alexander.sverdlin@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://lore.kernel.org/r/20230111132210.134478-1-linus.walleij@linaro.org
Signed-off-by: Arnd Bergmann <arnd@arndb.de>