MIPS: ralink: add memory definition for RT2880

Populate struct soc_info with the data that describes our RAM window.
Signed-off-by: John Crispin <blogic@openwrt.org>
Patchwork: http://patchwork.linux-mips.org/patch/5181/

arch/mips/include/asm/mach-ralink/rt288x.h

@@ -46,4 +46,8 @@
 
 #define CLKCFG_SRAM_CS_N_WDT		BIT(9)
 
+#define RT2880_SDRAM_BASE		0x08000000
+#define RT2880_MEM_SIZE_MIN		2
+#define RT2880_MEM_SIZE_MAX		128
+
 #endif

arch/mips/ralink/rt288x.c

@@ -136,4 +136,8 @@ void prom_soc_init(struct ralink_soc_info *soc_info)
 		name,
 		(id >> CHIP_ID_ID_SHIFT) & CHIP_ID_ID_MASK,
 		(id & CHIP_ID_REV_MASK));
+
+	soc_info->mem_base = RT2880_SDRAM_BASE;
+	soc_info->mem_size_min = RT2880_MEM_SIZE_MIN;
+	soc_info->mem_size_max = RT2880_MEM_SIZE_MAX;
 }