[ARM] 3706/2: ep93xx: add cirrus logic edb9315a support

Patch from Lennert Buytenhek

This patch adds support for the Cirrus Logic EDB9315A, an evaluation
board based on the Cirrus Logic EP9315 SoC, with 64M RAM, two USB host
ports, audio in/out, three serial ports, 10/100 ethernet, and IDE, VGA,
and LCD interfaces.

The EDB9315A is a low-cost version of the EDB9315, and has only 16M
of NOR flash, while the EDB9315 has 32M.

Signed-off-by: Lennert Buytenhek <buytenh@wantstofly.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>