drm/i2c: tda998x: select CONFIG_DRM_KMS_HELPER

drm/i2c: tda998x: select CONFIG_DRM_KMS_HELPER

This fails to build without the KMS helper functions:

x86_64-linux-ld: drivers/gpu/drm/bridge/tda998x_drv.o: in function `tda998x_detect_work':
tda998x_drv.c:(.text+0x4e6): undefined reference to `drm_kms_helper_hotplug_event'
x86_64-linux-ld: drivers/gpu/drm/bridge/tda998x_drv.o: in function `tda998x_bind':
tda998x_drv.c:(.text.unlikely+0x33): undefined reference to `drm_simple_encoder_init'
x86_64-linux-ld: drivers/gpu/drm/bridge/tda998x_drv.o:(.rodata+0x584): undefined reference to `drm_atomic_helper_connector_reset'
x86_64-linux-ld: drivers/gpu/drm/bridge/tda998x_drv.o:(.rodata+0x590): undefined reference to `drm_helper_probe_single_connector_modes'
x86_64-linux-ld: drivers/gpu/drm/bridge/tda998x_drv.o:(.rodata+0x5a4): undefined reference to `drm_atomic_helper_connector_duplicate_state'
x86_64-linux-ld: drivers/gpu/drm/bridge/tda998x_drv.o:(.rodata+0x5a8): undefined reference to `drm_atomic_helper_connector_destroy_state'

Select the missing symbol and fix up the broken whitespace.

Fixes: 325ba852d148 ("drm/i2c: move TDA998x driver under drivers/gpu/drm/bridge")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Neil Armstrong <neil.armstrong@linaro.org>
Link: https://lore.kernel.org/r/20250324210824.3094660-1-arnd@kernel.org
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>