ARM: implement relocation for ARM926

Change the implementation for arm926 to relocate the code to
an arbitrary address in RAM.

Adapt the TX25 (i.MX25), magnesium board to test the changes.

On the tx25 board TEXT_BASE is set to the final relocation
address to prevent one more copying of u-boot code
when relocating. More info see:
doc/README.arm-relocation

da850 board:
Tested-by: Ben Gardiner <bengardiner@nanometrics.ca>

Portions of this work were supported by funding from
the CE Linux Forum.

Signed-off-by: Heiko Schocher <hs@denx.de>
Cc: Ben Gardiner <bengardiner@nanometrics.ca>
diff --git a/board/logicpd/imx27lite/imx27lite.c b/board/logicpd/imx27lite/imx27lite.c
index 4427415..6eb5cc2 100644
--- a/board/logicpd/imx27lite/imx27lite.c
+++ b/board/logicpd/imx27lite/imx27lite.c
@@ -66,19 +66,22 @@
 
 int dram_init (void)
 {
+	/* dram_init must store complete ramsize in gd->ram_size */
+	gd->ram_size = get_ram_size((volatile void *)CONFIG_SYS_SDRAM_BASE,
+				PHYS_SDRAM_1_SIZE);
+	return 0;
+}
 
-#if CONFIG_NR_DRAM_BANKS > 0
-	gd->bd->bi_dram[0].start = PHYS_SDRAM_1;
-	gd->bd->bi_dram[0].size = get_ram_size((volatile void *)PHYS_SDRAM_1,
+void dram_init_banksize(void)
+{
+	gd->bd->bi_dram[0].start = CONFIG_SYS_SDRAM_BASE;
+	gd->bd->bi_dram[0].size = get_ram_size((volatile void *)CONFIG_SYS_SDRAM_BASE,
 			PHYS_SDRAM_1_SIZE);
-#endif
 #if CONFIG_NR_DRAM_BANKS > 1
 	gd->bd->bi_dram[1].start = PHYS_SDRAM_2;
 	gd->bd->bi_dram[1].size = get_ram_size((volatile void *)PHYS_SDRAM_2,
 			PHYS_SDRAM_2_SIZE);
 #endif
-
-	return 0;
 }
 
 int checkboard(void)