ASoC: rt7*-sdw: harden jack_detect_handler

ASoC: rt7*-sdw: harden jack_detect_handler

Realtek headset codec drivers typically check if the card is
instantiated before proceeding with the jack detection.

The rt700, rt711 and rt711-sdca are however missing a check on the
card pointer, which can lead to NULL dereferences encountered in
driver bind/unbind tests.

Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Reviewed-by: Rander Wang <rander.wang@intel.com>
Reviewed-by: Bard Liao <yung-chuan.liao@linux.intel.com>
Link: https://lore.kernel.org/r/20220606203752.144159-6-pierre-louis.bossart@linux.intel.com
Signed-off-by: Mark Brown <broonie@kernel.org>