[ARM] 2853/1: Make alloc_init_supersection() work with 36-bit mappings

[ARM] 2853/1: Make alloc_init_supersection() work with 36-bit mappings

Patch from Deepak Saxena

Working on adding support for 36-bit static mappings for ARMv6 and
Intel's XSC3 core and noticed that alloc_init_supersection currently
increments the phys addr by 1MB on each of the 16 iterations and then
forces alignment to supersection size (16MB).  This is really uneeded
b/c we have already forced the phys address to be 16MB aligned in
create_mapping(). Furthermore, this breaks 36-bit addressing b/c bits
[23:20] of the PMD contain bits [35:32] of the physical address and
the masking causes us to loose those bits thus ending up with an
incorrect virt -> phys translation.  The other option is to have an
alloc_init_supersection36.
Tested on Intel IXP2350 CPU with 36-bit static I/O mappings.

Signed-off-by: Deepak Saxena <dsaxena@plexity.net>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>