85xx: Add support for P2020RDB board

The code base adds P1 & P2 RDB platforms support.
The folder and file names can cater to future SOCs of P1/P2 family.
P1 & P2 processors are 85xx platforms, part of Freescale QorIQ series.

Tested following on P2020RDB:
1. eTSECs
2. DDR, NAND, NOR, I2C.

Signed-off-by: Poonam Aggrwal <poonam.aggrwal@freescale.com>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
diff --git a/include/asm-ppc/global_data.h b/include/asm-ppc/global_data.h
index a5747e1..db4b1ea 100644
--- a/include/asm-ppc/global_data.h
+++ b/include/asm-ppc/global_data.h
@@ -86,7 +86,7 @@
 	u32  mem_sec_clk;
 #endif /* CONFIG_MPC8360 */
 #endif
-#if defined(CONFIG_MPC837x) || defined(CONFIG_MPC8536)
+#if defined(CONFIG_FSL_ESDHC)
 	u32 sdhc_clk;
 #endif
 #if defined(CONFIG_MPC85xx) || defined(CONFIG_MPC86xx)