[ARM] 5182/1: pxa: Fix pcm990 compilation

Compiling pcm990 produces an error:

In file included from arch/arm/mach-pxa/pcm990-baseboard.c:25:
include/linux/ide.h:645: error: 'CONFIG_IDE_MAX_HWIFS' undeclared here (not in a function)

Fix it by removing unneeded header include.

Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>