ASoC: rt298: fix capture doesn't work at some cases

RT298_CBJ_CTRL1(0x4f) bit 10 is needed for headset capture. It
will be turned off when "VREF" widget is on and be turned on when
bias level is ON. It is odd. And if "VREF" is turned on in bias
level is ON, RT298_CBJ_CTRL1(0x4f) bit 10 will be turned off.
This patch move the bit control from rt298_set_bias_level and
rt298_vref_event to rt298_jack_detect. So it will be turned on
once a jack is plugged in.

Signed-off-by: Bard Liao <bardliao@realtek.com>
Signed-off-by: Mark Brown <broonie@kernel.org>