phy: cadence: Add driver for Sierra PHY

Add a Sierra PHY driver with PCIe and USB support.

The PHY has multiple lanes, which can be configured into
groups, and a generic PHY device is created for each group.

There are two resets controlling the overall PHY block, one
to enable the APB interface for programming registers, and
another to enable the PHY itself.  Additionally there are
resets for each PHY lane.

The PHY can be configured in hardware to read register
settings from ROM, or they can be written by the driver.

The sequence of operation on startup is to enable the APB
bus, write the PHY registers (if required)  for each lane
group, and then enable the PHY.  Each group of lanes
can then be individually controlled using the power_on()/
power_off() function for that generic PHY
Signed-off-by: Alan Douglas <adouglas@cadence.com>
Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>

drivers/phy/cadence/Kconfig

 #
-# Phy driver for Cadence MHDP DisplayPort controller
+# Phy drivers for Cadence PHYs
 #
 config PHY_CADENCE_DP
 	tristate "Cadence MHDP DisplayPort PHY driver"
@@ -8,3 +8,10 @@ config PHY_CADENCE_DP
 	select GENERIC_PHY
 	help
 	  Support for Cadence MHDP DisplayPort PHY.
+
+config PHY_CADENCE_SIERRA
+	tristate "Cadence Sierra PHY Driver"
+	depends on OF && HAS_IOMEM && RESET_CONTROLLER
+	select GENERIC_PHY
+	help
+	  Enable this to support the Cadence Sierra PHY driver
\ No newline at end of file

drivers/phy/cadence/Makefile

 obj-$(CONFIG_PHY_CADENCE_DP)	+= phy-cadence-dp.o
+obj-$(CONFIG_PHY_CADENCE_SIERRA)	+= phy-cadence-sierra.o