bmips: add support for Netgear DGND3700 v1, DGND3800B

The Netgear DGND3700 v1 and DGND3800B are the same device but with
different factory firmwares. It's an xDSL wifi router with a slim black
shiny casing and 4 PCB internal antennas connected via UFL to a miniPCI
detachable card.

Hardware:
 - SoC: Broadcom BCM6368
 - CPU: dual core BMIPS4350 V3.1 @400Mhz
 - RAM: 128 MB DDR
 - NOR Flash: 32 MB parallel (CFE and OS)
 - NAND flash: 128 MB (empty)
 - Ethernet LAN: 5x 1Gbit
 - Wifi 2.4 GHz: Broadcom BCM43222 802.11bgn
 - Wifi 5 GHz: Broadcom BCM43222 802.11abgn
 - USB: 2x 2.0
 - Buttons: 3x, 1 reset
 - LEDs: 11x
 - UART: yes

Installation via OEM web UI:
  1. Open the Netgear administration web interface, by default:
        http://192.168.0.1
	user: admin
        password: password
  2. Look for "upgrade firmware" and proceed
  3. Wait some minutes until it finishes

Signed-off-by: Daniel González Cabanelas <dgcbueu@gmail.com>

target/linux/bmips/image/Makefile

@@ -313,6 +313,15 @@ define Device/bcm63xx-nand
   DEVICE_PACKAGES += nand-utils
 endef
 
+define Device/bcm63xx_netgear
+  $(Device/bcm63xx-cfe)
+  DEVICE_VENDOR := NETGEAR
+  IMAGES := factory.chk sysupgrade.bin
+  IMAGE/factory.chk := cfe-bin | netgear-chk
+  NETGEAR_BOARD_ID :=
+  NETGEAR_REGION :=
+endef
+
 define Device/sercomm-nand
   $(Device/bcm63xx-nand)
   IMAGES := factory.img sysupgrade.bin

target/linux/bmips/image/bcm6368.mk

@@ -14,6 +14,35 @@ define Device/comtrend_vr-3025u
 endef
 TARGET_DEVICES += comtrend_vr-3025u
 
+define Device/netgear_dgnd3700-v1
+  $(Device/bcm63xx_netgear)
+  DEVICE_VENDOR := NETGEAR
+  DEVICE_MODEL := DGND3700
+  DEVICE_VARIANT := v1
+  CFE_BOARD_ID := 96368MVWG
+  CHIP_ID := 6368
+  BLOCKSIZE := 0x20000
+  NETGEAR_BOARD_ID := U12L144T01_NETGEAR_NEWLED
+  NETGEAR_REGION := 1
+  DEVICE_PACKAGES += $(USB2_PACKAGES) \
+    $(B43_PACKAGES)
+endef
+TARGET_DEVICES += netgear_dgnd3700-v1
+
+define Device/netgear_dgnd3800b
+  $(Device/bcm63xx_netgear)
+  DEVICE_VENDOR := NETGEAR
+  DEVICE_MODEL := DGND3800B
+  CFE_BOARD_ID := 96368MVWG
+  CHIP_ID := 6368
+  BLOCKSIZE := 0x20000
+  NETGEAR_BOARD_ID := U12L144T11_NETGEAR_NEWLED
+  NETGEAR_REGION := 1
+  DEVICE_PACKAGES += $(USB2_PACKAGES) \
+    $(B43_PACKAGES)
+endef
+TARGET_DEVICES += netgear_dgnd3800b
+
 define Device/observa_vh4032n
   $(Device/bcm63xx-cfe)
   DEVICE_VENDOR := Observa