i.MX28: Fix initial stack pointer position

The patch:

  m28evk: Use GENERATED_GBL_DATA_SIZE
  commit 1084606c972ea5f1d89f69bdbd978b867d0ee521

introduced usage of GENERATED_GBL_DATA_SIZE and calculation of initial stack
pointer position defived from that. Due to a small typo, the SP position moved
to 0x21f80, which is past the SRAM area. This didn't manifest on the real
hardware as the SRAM repeats there (address bits in the CPU being ignored).

Though this was caught in QEMU, where it crashed the emulator.

Signed-off-by: Marek Vasut <marex@denx.de>
Cc: Stefano Babic <sbabic@denx.de>
Cc: Fabio Estevam <fabio.estevam@freescale.com>
Tested-by: Fabio Estevam <fabio.estevam@freescale.com>
diff --git a/include/configs/mx28evk.h b/include/configs/mx28evk.h
index 705fdab..02f3366 100644
--- a/include/configs/mx28evk.h
+++ b/include/configs/mx28evk.h
@@ -81,7 +81,7 @@
 #define CONFIG_SYS_SDRAM_BASE		PHYS_SDRAM_1
 /* Point initial SP in SRAM so SPL can use it too. */
 
-#define CONFIG_SYS_INIT_RAM_ADDR	0x00002000
+#define CONFIG_SYS_INIT_RAM_ADDR	0x00000000
 #define CONFIG_SYS_INIT_RAM_SIZE	(128 * 1024)
 
 #define CONFIG_SYS_INIT_SP_OFFSET \