On 5XX targets we need to program the bit of the highest DDR bank
into a number of registers, one of which is protected which would
cause problems if the user mode driver tried to write to it.
Specify the high bank bit in the device tree files, set the
problematic register in the kernel and then pass the value up to
the user mode driver as a property and let them program the
other registers. This makes the device tree the authoratative
source of the high bit value which is exactly how it should be.
If the value isn't specified by the device tree for whatever reason
return an error for the property request - that will give the UMD
a clue that the value wasn't specified and they should just set a
default.
CRs-Fixed: 970272
Change-Id: Ic0dedbad830321329b74da7fa3e172fdaf765c4d
Signed-off-by: Jordan Crouse <jcrouse@codeaurora.org>