imx: fix USB support

The ChipIdea USB kernel driver gained support for disabling glue drivers
in 5.8, see upstream commmit: 95caa2ae70fd ("usb: chipidea: allow
disabling glue drivers if EMBEDDED").

This enables 'CONFIG_USB_CHIPIDEA_IMX' in the 'imx' target kernel config
which brings back USB support.

Signed-off-by: Piotr Dymacz <pepe2k@gmail.com>

target/linux/imx/config-5.10

@@ -396,6 +396,7 @@ CONFIG_UNWINDER_ARM=y
 CONFIG_USB=y
 CONFIG_USB_CHIPIDEA=y
 CONFIG_USB_CHIPIDEA_HOST=y
+CONFIG_USB_CHIPIDEA_IMX=y
 CONFIG_USB_CHIPIDEA_UDC=y
 CONFIG_USB_COMMON=y
 CONFIG_USB_EHCI_HCD=y