configs: imx8mp_evk: revert to old ram settings

The 'commit 864ac2cf383e ("board: imx8mp: Add Engicam
i.Core MX8M Plus EDIMM2.2 Starter Kit")' has changed the imx8mp evk ram
settings from 6GB ram to 2GB.

This changeset reverts the above change.

Signed-off-by: Manoj Sai <abbaraju.manojsai@amarulasolutions.com>
Reported-by  : Peter Bergin <peter@berginkonsult.se>
Reviewed-by: Peng Fan <peng.fan@nxp.com>
Reviewed-by: Fabio Estevam <festevam@denx.de>
diff --git a/include/configs/imx8mp_evk.h b/include/configs/imx8mp_evk.h
index 1fea5b7..1759318 100644
--- a/include/configs/imx8mp_evk.h
+++ b/include/configs/imx8mp_evk.h
@@ -46,9 +46,11 @@
 #define CFG_SYS_INIT_RAM_SIZE	0x80000
 
 
-/* Totally 2GB DDR */
+/* Totally 6GB DDR */
 #define CFG_SYS_SDRAM_BASE		0x40000000
 #define PHYS_SDRAM			0x40000000
-#define PHYS_SDRAM_SIZE			0x80000000
+#define PHYS_SDRAM_SIZE			0xC0000000	/* 3 GB */
+#define PHYS_SDRAM_2			0x100000000
+#define PHYS_SDRAM_2_SIZE		0xC0000000	/* 3 GB */
 
 #endif