drm/bridge: it66121: acquire reset GPIO in probe

drm/bridge: it66121: acquire reset GPIO in probe

The it66121_ctx structure has a gpio_reset field, and it66121_hw_reset()
calls gpiod_set_value() on it. However, the GPIO descriptor is never
acquired via devm_gpiod_get(), leaving gpio_reset as NULL throughout
the driver lifetime.

gpiod_set_value() silently returns when passed a NULL descriptor, so
the hardware reset sequence in it66121_hw_reset() is a no-op. This
leaves the chip in an undefined state at probe time, which can prevent
it from responding on the I2C bus.

The DT binding marks reset-gpios as a required property, so all
compliant device trees provide this GPIO. Add the missing
devm_gpiod_get() call after enabling power supplies and before the
hardware reset, so the chip is properly reset with power applied.

Fixes: 988156dc2fc9 ("drm: bridge: add it66121 driver")
Cc: stable@vger.kernel.org
Signed-off-by: Julien Chauveau <chauveau.julien@gmail.com>
Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
Tested-by: Javier Martinez Canillas <javierm@redhat.com>
Link: https://patch.msgid.link/20260324193011.16583-1-chauveau.julien@gmail.com
Signed-off-by: Javier Martinez Canillas <javierm@redhat.com>