phy: samsung-ufs: add UFS PHY driver for samsung SoC

phy: samsung-ufs: add UFS PHY driver for samsung SoC

This patch introduces Samsung UFS PHY driver. This driver
supports to deal with phy calibration and power control
according to UFS host driver's behavior.

[Robot: -Wmissing-prototypes and -Wsometimes-uninitialized]
Reported-by: kernel test robot <lkp@intel.com>
Reviewed-by: Kiwoong Kim <kwmad.kim@samsung.com>
Signed-off-by: Seungwon Jeon <essuuj@gmail.com>
Signed-off-by: Alim Akhtar <alim.akhtar@samsung.com>
Cc: Kishon Vijay Abraham I <kishon@ti.com>
Cc: Vinod Koul <vkoul@kernel.org>
Tested-by: Paweł Chmiel <pawel.mikolaj.chmiel@gmail.com>
Link: https://lore.kernel.org/r/20200716192217.35740-2-alim.akhtar@samsung.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>