board: ls1012a: LS1012A-2G5RDB board support

LS1012A-2G5RDB belongs to LS1012A family with features 2 2.5G SGMII
PFE MAC, SATA, USB 2.0/3.0, WiFi DDR, eMMC, QuadSPI, UART.

Signed-off-by: Bhaskar Upadhaya <Bhaskar.Upadhaya@nxp.com>
Reviewed-by: York Sun <york.sun@nxp.com>
diff --git a/board/freescale/ls1012ardb/README b/board/freescale/ls1012ardb/README
index 453b432..572fd8c 100644
--- a/board/freescale/ls1012ardb/README
+++ b/board/freescale/ls1012ardb/README
@@ -52,3 +52,46 @@
 U-boot Env 	| 1MB	| 0x4020_0000
 PPA FIT image	| 2MB	| 0x4050_0000
 Linux ITB	| ~53MB | 0x40A0_0000
+
+LS1012A2G5RDB board Overview
+-----------------------
+ - SERDES Connections, 3 lanes supporting:
+      - SGMII, SGMII 2.5
+      - SATA 3.0
+ - DDR Controller
+     - 16-bit, 1 GB DDR3L SDRAM memory, running at data rates up to 1 GT/s
+ -QSPI: A dual 1:3 switch, NX3L4357GM,115 (U35) drives the QSPI chip-select
+ signals to
+    - QSPI NOR flash memory
+ - USB 3.0
+    - one high-speed USB 2.0/3.0 port.
+ - SDIO WiFi, SPI
+ - 2 I2C controllers
+ - One SATA onboard connectors
+ - UART
+   - The LS1012A processor consists of two UART controllers,
+   out of which only UART1 is used on 2G5RDB.
+ - ARM JTAG support
+
+Major Difference between LS1012ARDB and LS1012A-2G5RDB
+------------------------------------------------------
+1. LS1012A-2G5RDB has Type C USB connector unlike USB Type A/B of LS1012ARDB
+2. LS1012A-2G5RDB has 2 2.5G AQR PHY unlike 2 1G Realtek RTL8211FS PHYs
+   of LS1012ARDB
+3. LS1012A-2G5RDB is not having Arduino header
+4. LS1012A-2G5RDB doesn't have PCI slot
+
+Booting Options
+---------------
+QSPI Flash
+
+QSPI flash map
+--------------
+Images		| Size	|QSPI Flash Address
+------------------------------------------
+RCW + PBI	| 1MB	| 0x4000_0000
+U-boot 		| 1MB	| 0x4010_0000
+U-boot Env 	| 1MB	| 0x4030_0000
+PPA FIT image	| 2MB	| 0x4040_0000
+PFE firmware	| 20K	| 0x00a0_0000
+Linux ITB	| ~53MB | 0x4100_0000