usb: phy: Add STi USB2 PHY

This is the generic phy driver for the picoPHY ports
used by USB2/1.1 controllers. It is found on STiH407 SoC
family from STMicroelectronics.

Signed-off-by: Patrice Chotard <patrice.chotard@st.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
diff --git a/drivers/phy/Makefile b/drivers/phy/Makefile
index ab56c46..668040b 100644
--- a/drivers/phy/Makefile
+++ b/drivers/phy/Makefile
@@ -9,3 +9,4 @@
 obj-$(CONFIG_$(SPL_)NOP_PHY) += nop-phy.o
 obj-$(CONFIG_PHY_SANDBOX) += sandbox-phy.o
 obj-$(CONFIG_$(SPL_)PIPE3_PHY) += ti-pipe3-phy.o
+obj-$(CONFIG_STI_USB_PHY) += sti_usb_phy.o