ramips: remove duplicate DEVICE_PACKAGES for TP-Link Archer C20i

DEVICE_PACKAGES is specified twice for the same device. Remove the
first (=older) assignment.

Fixes: 40692f0fb5 ("ramips: mt7620: select only the matching mt76 driver")

Signed-off-by: Adrian Schmutzler <freifunk@adrianschmutzler.de>
(cherry picked from commit 4ecd6510bf)

target/linux/ramips/image/mt7620.mk

@@ -94,7 +94,6 @@ define Device/ArcherC20i
   TPLINK_HWID := 0xc2000001
   TPLINK_HWREV := 58
   IMAGES += factory.bin
-  DEVICE_PACKAGES := kmod-mt76x0e
   DEVICE_TITLE := TP-Link ArcherC20i
   DEVICE_PACKAGES := kmod-mt76x0e kmod-usb2 kmod-usb-ohci
 endef