[ARM] 3125/2: VR1000: Fix map_decs initialiser

Patch from Ben Dooks

Fix the initialisation of the map_desc fields
in the Thorcom VR1000 machine support to use
the new .pfn initialiser.

Signed-off-by: Ben Dooks <ben-linux@fluff.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>