Kconfig: USB: Migrate CONFIG_USB_EHCI_HCD users to Kconfig

Migrate the rest of the users of CONFIG_USB_EHCI_HCD over to Kconfig.
For a few SoCs, imply or default y this if USB is enabled.  In some
cases we had not already migrated to CONFIG_USB so do that as well.

Cc: Marek Vasut <marex@denx.de>
Signed-off-by: Tom Rini <trini@konsulko.com>
Reviewed-by: Marek Vasut <marex@denx.de>
diff --git a/configs/medcom-wide_defconfig b/configs/medcom-wide_defconfig
index a811506..e30ac75 100644
--- a/configs/medcom-wide_defconfig
+++ b/configs/medcom-wide_defconfig
@@ -32,6 +32,7 @@
 CONFIG_SYS_NS16550=y
 CONFIG_USB=y
 CONFIG_DM_USB=y
+CONFIG_USB_EHCI_HCD=y
 CONFIG_USB_STORAGE=y
 CONFIG_DM_VIDEO=y
 CONFIG_VIDEO_TEGRA20=y