drm/bridge: tpd12s015: Drop buggy __exit annotation for remove function

With tpd12s015_remove() marked with __exit this function is discarded
when the driver is compiled as a built-in. The result is that when the
driver unbinds there is no cleanup done which results in resource
leakage or worse.

Fixes: cff5e6f7 ("drm/bridge: Add driver for the TI TPD12S015 HDMI level shifter")
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Link: https://patchwork.freedesktop.org/patch/msgid/20231102165640.3307820-19-u.kleine-koenig@pengutronix.de