ARM: dts: msm: keep UFS phy regulator always on for SM8150

We may see some glitch on UFS host TX when turning on/off the UFS PHY
regulator, this change keeps this regulator always ON but still tries
to keep the regulator in LPM mode.

Change-Id: Ie670f7a64e1ceb432777810f9abc681fdf56604e
Signed-off-by: Subhash Jadavani <subhashj@codeaurora.org>