ARM: move iotable mappings within the vmalloc region

In order to remove the build time variation between different SOCs with
regards to VMALLOC_END, the iotable mappings are now allocated inside
the vmalloc region.  This allows for VMALLOC_END to be identical across
all machines.

The value for VMALLOC_END is now set to 0xff000000 which is right where
the consistent DMA area starts.

To accommodate all static mappings on machines with possible highmem usage,
the default vmalloc area size is changed to 240 MB so that VMALLOC_START
is no higher than 0xf0000000 by default.

Signed-off-by: Nicolas Pitre <nicolas.pitre@linaro.org>
Tested-by: Stephen Warren <swarren@nvidia.com>
Tested-by: Kevin Hilman <khilman@ti.com>
Tested-by: Jamie Iles <jamie@jamieiles.com>
diff --git a/Documentation/arm/memory.txt b/Documentation/arm/memory.txt
index 771d48d..208a2d4 100644
--- a/Documentation/arm/memory.txt
+++ b/Documentation/arm/memory.txt
@@ -51,15 +51,14 @@
 ff000000	ffbfffff	Reserved for future expansion of DMA
 				mapping region.
 
-VMALLOC_END	feffffff	Free for platform use, recommended.
-				VMALLOC_END must be aligned to a 2MB
-				boundary.
-
 VMALLOC_START	VMALLOC_END-1	vmalloc() / ioremap() space.
 				Memory returned by vmalloc/ioremap will
 				be dynamically placed in this region.
-				VMALLOC_START may be based upon the value
-				of the high_memory variable.
+				Machine specific static mappings are also
+				located here through iotable_init().
+				VMALLOC_START is based upon the value
+				of the high_memory variable, and VMALLOC_END
+				is equal to 0xff000000.
 
 PAGE_OFFSET	high_memory-1	Kernel direct-mapped RAM region.
 				This maps the platforms RAM, and typically