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/Kconfig b/drivers/Kconfig
index a096dad..a5f24d7 100644
--- a/drivers/Kconfig
+++ b/drivers/Kconfig
@@ -54,6 +54,8 @@
 
 source "drivers/pcmcia/Kconfig"
 
+source "drivers/phy/Kconfig"
+
 source "drivers/phy/marvell/Kconfig"
 
 source "drivers/pinctrl/Kconfig"