ramips: add support for PandoraBox PBR-M1

This patch is for PandoraBox PBR-M1 which is based on mt7621,
all the features work fine, including rtc, leds, button, usb3.0, etc.

Signed-off-by: tymon <banglang.huang@foxmail.com>

SVN-Revision: 46041

target/linux/ramips/base-files/lib/ramips.sh

@@ -247,6 +247,9 @@ ramips_board_detect() {
 	*"OLinuXino-RT5350F-EVB")
 		name="olinuxino-rt5350f-evb"
 		;;
+	*"PBR-M1")
+		name="pbr-m1"
+		;;
 	*"Petatel PSR-680W"*)
 		name="psr-680w"
 		;;