ar71xx: image: fix typo in MTDPARTS def for qihoo-c301

Reported-by: Syrone Wong <wong.syrone@gmail.com>
Signed-off-by: Yousong Zhou <yszhou4tech@gmail.com>

target/linux/ar71xx/image/generic.mk

@@ -509,7 +509,7 @@ $(Device/seama)
   DEVICE_PACKAGES :=  kmod-usb-core kmod-usb2 kmod-ledtrig-usbdev kmod-ath10k
   BOARDNAME = QIHOO-C301
   IMAGE_SIZE = 15744k
-  MTDPARTS = mtdparts=spi0.0:256k(u-boot)ro,64k(u-boot-env),64k(devdata),64k(devconf),15744k(firmware),64k(warm_start),64k(action_image_config),64k(radiocfg)ro;spi0.1:15360k(upgrade2),1024k(privatedata)
+  MTDPARTS = spi0.0:256k(u-boot)ro,64k(u-boot-env),64k(devdata),64k(devconf),15744k(firmware),64k(warm_start),64k(action_image_config),64k(radiocfg)ro;spi0.1:15360k(upgrade2),1024k(privatedata)
   SEAMA_SIGNATURE := wrgac26_qihoo360_360rg
 endef