mpc8641: Support 36-bit physical addressing

This patch creates a memory map with all the devices
in 36-bit physical space, in addition to the 32-bit map.
The CCSR relocation is moved (again, sorry) to
allow for the physical address to be 36 bits - this
requires translation to be enabled.  With 36-bit physical
addressing enabled, we are no longer running with VA=PA
translations.  This means we have to distinguish between
the two in the config file.  The existing region name is
used to indicate the virtual address, and a _PHYS variety
is created to represent the physical address.

Large physical addressing is not enabled by default.
Set CONFIG_PHYS_64BIT in the config file to turn this on.

Signed-off-by: Becky Bruce <becky.bruce@freescale.com>
diff --git a/doc/README.mpc8641hpcn b/doc/README.mpc8641hpcn
index 0a6e715..5ac39e6 100644
--- a/doc/README.mpc8641hpcn
+++ b/doc/README.mpc8641hpcn
@@ -113,6 +113,9 @@
 -------------
 NOTE:  RIO and PCI are mutually exclusive, so they share an address
 
+For 32-bit u-boot, devices are mapped so that the virtual address ==
+the physical address, and the map looks liks this:
+
 	Memory Range			Device		Size
 	------------			------		----
 	0x0000_0000	0x7fff_ffff	DDR		2G
@@ -127,6 +130,27 @@
 	0xffc1_0000	0xffc1_ffff	PCI2/PEX2 IO	64K
 	0xef80_0000	0xefff_ffff	Flash		8M
 
+For 36-bit-enabled u-boot, the virtual map is the same as for 32-bit.
+However, the physical map is altered to reside in 36-bit space, as follows.
+Addresses are no longer mapped with VA == PA.  All accesses from
+software use the VA; the PA is only used for setting up windows
+and mappings. Note that the low 32 bits are the same as the VA above;
+only the top 4 bits vary:
+
+	Memory Range			Device		Size
+	------------			------		----
+	0x0_0000_0000	0x0_7fff_ffff	DDR		2G
+	0xc_8000_0000	0xc_9fff_ffff	RIO MEM		512M
+	0xc_8000_0000	0xc_9fff_ffff	PCI1/PEX1 MEM	512M
+	0xc_a000_0000	0xc_bfff_ffff	PCI2/PEX2 MEM	512M
+	0xf_ffe0_0000	0xf_ffef_ffff	CCSR		1M
+	0xf_ffdf_0000	0xf_ffdf_7fff	PIXIS		8K
+	0xf_ffdf_8000	0xf_ffdf_ffff	CF		8K
+	0x0_f840_0000	0xf_f840_3fff	Stack space	32K
+	0xf_ffc0_0000	0xf_ffc0_ffff	PCI1/PEX1 IO	64K
+	0xf_ffc1_0000	0xf_ffc1_ffff	PCI2/PEX2 IO	64K
+	0xf_ef80_0000	0xf_efff_ffff	Flash		8M
+
 5. pixis_reset command
 --------------------
 A new command, "pixis_reset", is introduced to reset mpc8641hpcn board