gemini: Activate USB support again

This activates the CONFIG_USB_SUPPORT option in the in the gemini kernel
again which will provide the core USB support and makes it possible to
compile the rest of the USB parts into modules. Without this change USB
will not be available in the gemini target and some modules fail to
compile because the feature list indicates USB support.

Fixes: 10ec966f7b ("gemini: Break out USB to packages")
Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>

target/linux/gemini/config-4.14

@@ -415,6 +415,7 @@ CONFIG_TMPFS_POSIX_ACL=y
 CONFIG_TREE_SRCU=y
 CONFIG_UNCOMPRESS_INCLUDE="debug/uncompress.h"
 CONFIG_UNINLINE_SPIN_UNLOCK=y
+CONFIG_USB_SUPPORT=y
 # CONFIG_USERIO is not set
 CONFIG_USER_NS=y
 CONFIG_USE_OF=y