ARM: dts: msm: Make Rx and Tx supplies dynamic for WCD9335 in QCS405

LDO6 is not entering into the LPM mode as TX and RX supplies current
is not set to zero. Make WCD9335 RX and Tx supplies as dynamic to vote
the regulator on SND_SOC_DAPM_PRE_PMU widget event and unvote on
SND_SOC_DAPM_POST_PMD event. Set current to zero during unvote.

Change-Id: Ia34da9c0668b0150c684000d110efbabc7232c8b
Signed-off-by: Mangesh Kunchamwar <mangeshk@codeaurora.org>
Signed-off-by: Surendar Karka <skarka@codeaurora.org>