MIPS: Add Onion Omega2+ board

The Onion Omega2+ is an MT7688A based board that has 128MB RAM and
multiple peripherals.

The MT7688A is pin compatible with the MT7628A, although the former
supports a 1T1R antenna whereas the MT7628A supports a 2R2T antenna.
Signed-off-by: Harvey Hunt <harvey.hunt@imgtec.com>
Cc: robh+dt@kernel.org
Cc: mark.rutland@arm.com
Cc: john@phrozen.org
Cc: linux-kernel@vger.kernel.org
Cc: devicetree@vger.kernel.org
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/17137/Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

MAINTAINERS

@@ -9674,6 +9674,12 @@ F:	drivers/regulator/twl-regulator.c
 F:	drivers/regulator/twl6030-regulator.c
 F:	include/linux/i2c-omap.h
 
+ONION OMEGA2+ BOARD
+M:	Harvey Hunt <harveyhuntnexus@gmail.com>
+L:	linux-mips@linux-mips.org
+S:	Maintained
+F:	arch/mips/boot/dts/ralink/omega2p.dts
+
 OMFS FILESYSTEM
 M:	Bob Copeland <me@bobcopeland.com>
 L:	linux-karma-devel@lists.sourceforge.net

arch/mips/boot/dts/ralink/Makefile

@@ -2,6 +2,7 @@ dtb-$(CONFIG_DTB_RT2880_EVAL)	+= rt2880_eval.dtb
 dtb-$(CONFIG_DTB_RT305X_EVAL)	+= rt3052_eval.dtb
 dtb-$(CONFIG_DTB_RT3883_EVAL)	+= rt3883_eval.dtb
 dtb-$(CONFIG_DTB_MT7620A_EVAL)	+= mt7620a_eval.dtb
+dtb-$(CONFIG_DTB_OMEGA2P)	+= omega2p.dtb
 dtb-$(CONFIG_DTB_VOCORE2)	+= vocore2.dtb
 
 obj-y				+= $(patsubst %.dtb, %.dtb.o, $(dtb-y))

arch/mips/boot/dts/ralink/omega2p.dts

+/dts-v1/;
+
+/include/ "mt7628a.dtsi"
+
+/ {
+	compatible = "onion,omega2+", "ralink,mt7688a-soc", "ralink,mt7628a-soc";
+	model = "Onion Omega2+";
+
+	memory@0 {
+		device_type = "memory";
+		reg = <0x0 0x8000000>;
+	};
+
+	chosen {
+		bootargs = "console=ttyS0,115200";
+		stdout-path = &uart0;
+	};
+};

arch/mips/ralink/Kconfig

@@ -82,6 +82,11 @@ choice
 		depends on SOC_MT7620
 		select BUILTIN_DTB
 
+	config DTB_OMEGA2P
+		bool "Onion Omega2+"
+		depends on SOC_MT7620
+		select BUILTIN_DTB
+
 	config DTB_VOCORE2
 		bool "VoCore2"
 		depends on SOC_MT7620