usb: Kconfig: Add Kconfigs entry USB_EHCI_ZYNQ

Add Kconfig entry config option for USB_EHCI_ZYNQ
and update the same to enable for all zynq boards
which supports USB

Signed-off-by: Siva Durga Prasad Paladugu <sivadur@xilinx.com>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>
diff --git a/configs/zynq_zed_defconfig b/configs/zynq_zed_defconfig
index 7783eeb..c23e664 100644
--- a/configs/zynq_zed_defconfig
+++ b/configs/zynq_zed_defconfig
@@ -37,6 +37,8 @@
 CONFIG_ZYNQ_GEM=y
 CONFIG_ZYNQ_QSPI=y
 CONFIG_USB=y
+CONFIG_USB_EHCI_HCD=y
+CONFIG_USB_EHCI=y
 CONFIG_USB_ULPI_VIEWPORT=y
 CONFIG_USB_ULPI=y
 CONFIG_USB_GADGET=y