arm: mvebu: Move PCI(e) MBUS window to end of RAM

With patch 49b23e035d96 (pci: mvebu: Increase size of PCIe default mapping)
the mapping size for each PCI(e) controller was increased from 32MiB to
128MiB. This leads to problems on boards with multiple PCIe slots / ports
which are unable to map all PCIe ports, e.g. the Armada-XP theadorable:

DRAM:  2 GiB (667 MHz, 64-bit, ECC not enabled)
SF: Detected m25p128 with page size 256 Bytes, erase size 256 KiB, total 16 MiB
Cannot add window '4:f8', conflicts with another window
PCIe unable to add mbus window for mem at f0000000+08000000
Model: Marvell Armada XP theadorable

This patch moves the base address for the PCI(e) memory spaces from
0xe8000000 to the end of SDRAM (clipped to a max of 0xc0000000 right now).
This gives move room and flexibility for PCI(e) mappings.

Signed-off-by: Stefan Roese <sr@denx.de>
Cc: VlaoMao <vlaomao@gmail.com>
Tested-by: VlaoMao <vlaomao at gmail.com>
diff --git a/arch/arm/mach-mvebu/dram.c b/arch/arm/mach-mvebu/dram.c
index 68383d0..fa8c799 100644
--- a/arch/arm/mach-mvebu/dram.c
+++ b/arch/arm/mach-mvebu/dram.c
@@ -33,7 +33,9 @@
 #define REG_CPUCS_WIN_WIN0_CS(x)	(((x) & 0x3) << 2)
 #define REG_CPUCS_WIN_SIZE(x)		(((x) & 0xff) << 24)
 
-#define SDRAM_SIZE_MAX			0xc0000000
+#ifndef MVEBU_SDRAM_SIZE_MAX
+#define MVEBU_SDRAM_SIZE_MAX		0xc0000000
+#endif
 
 #define SCRUB_MAGIC		0xbeefdead
 
@@ -275,8 +277,8 @@
 		 * address space left for the internal registers etc.
 		 */
 		size += mvebu_sdram_bs(i);
-		if (size > SDRAM_SIZE_MAX)
-			size = SDRAM_SIZE_MAX;
+		if (size > MVEBU_SDRAM_SIZE_MAX)
+			size = MVEBU_SDRAM_SIZE_MAX;
 	}
 
 	for (; i < CONFIG_NR_DRAM_BANKS; i++) {
@@ -312,7 +314,7 @@
 
 		/* Clip the banksize to 1GiB if it exceeds the max size */
 		size += gd->bd->bi_dram[i].size;
-		if (size > SDRAM_SIZE_MAX)
+		if (size > MVEBU_SDRAM_SIZE_MAX)
 			mvebu_sdram_bs_set(i, 0x40000000);
 	}