ARM: 6168/1: ep93xx: move physmap flash registration into core.c

Create a core.c __init function to handle the physmap flash
registration for all the ep93xx platforms.  Also, modify all
the ep93xx platforms to use this new function.

This simplifies all the ep93xx platform init code and reduces
the size of the kernel when including multiple ep93xx boards.

Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Acked-by: Ryan Mallon <ryan@bluewatersys.com>
Acked-by: Martin Guy <martinwguy@gmail.com>
Acked-by: Hubert Feurstein <hubert.feurstein@contec.at>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>