HACK/ramips: remove the usb and rtc features

The RM2100 doesn't have them.

Signed-off-by: Rui Salvaterra <[email protected]>

target/linux/ramips/mt7621/target.mk

@@ -4,7 +4,7 @@
 
 SUBTARGET:=mt7621
 BOARDNAME:=MT7621 based boards
-FEATURES+=nand ramdisk rtc usb minor
+FEATURES+=nand ramdisk
 CPU_TYPE:=24kc
 KERNELNAME:=vmlinux vmlinuz
 # make Kernel/CopyImage use $LINUX_DIR/vmlinuz