phy: qcom-ufs: add UFS HS-G4 support

New generation (3.0) UFS devices are capable of running at HS-G4
(High Speed Gear 4) mode which is 2x faster than previous generation
UFS devices. However, if the connected UFS device is only capable of HS-G3
at maximum, putting the UFS PHY to its HS-G4 settings would cause power
penalty. This change adds a boolean variable to the PHY calibration API to
allow the callers tell the calibration API whether HS-G3 or HS-G4 settings
should be configured. The value of this boolean variable is decided by the
UFS PHY's submode.

Change-Id: Id2e5fc2285e71ae07ab3b9a19c2aa3937ad465c8
Signed-off-by: Can Guo <cang@codeaurora.org>