phy: msm-sata: Add support for 6Gbps SATA PHY on MSM platforms

Add a phy driver that binds with MSM AHCI SATA controller driver
to initialize the SATA host on various MSM platforms like APQ8084,
MPQ8092 etc.

Change-Id: I7b381bac6c19709628a5ad84feef913065880820
Signed-off-by: Sujit Reddy Thumma <sthumma@codeaurora.org>