drivers: phy: add generic PHY framework

The PHY framework provides a set of APIs to control a PHY. This API is
derived from the linux version of the generic PHY framework.
Currently the API supports init(), deinit(), power_on, power_off() and
reset(). The framework provides a way to get a reference to a phy from the
device-tree.

Signed-off-by: Jean-Jacques Hiblot <jjhiblot@ti.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
diff --git a/drivers/Makefile b/drivers/Makefile
index 4a4b237..6916420 100644
--- a/drivers/Makefile
+++ b/drivers/Makefile
@@ -5,6 +5,7 @@
 obj-$(CONFIG_$(SPL_TPL_)DM)	+= core/
 obj-$(CONFIG_$(SPL_)CLK)	+= clk/
 obj-$(CONFIG_$(SPL_)LED)	+= led/
+obj-$(CONFIG_$(SPL_)PHY)	+= phy/
 obj-$(CONFIG_$(SPL_)PINCTRL)	+= pinctrl/
 obj-$(CONFIG_$(SPL_)RAM)	+= ram/