arm: omap1: add missing includes

Add missing includes to get rid of the following sparse warnings:

arch/arm/mach-omap1/devices.c:225:13: warning: symbol 'omap1_camera_init' was not declared. Should it be static?
arch/arm/mach-omap1/flash.c:15:6: warning: symbol 'omap1_set_vpp' was not declared. Should it be static?
arch/arm/mach-omap1/serial.c:190:6: warning: symbol 'omap_serial_wake_trigger' was not declared. Should it be static?
arch/arm/mach-omap1/time.c:252:18: warning: symbol 'omap_timer' was not declared. Should it be static?

Signed-off-by: Aaro Koskinen <aaro.koskinen@nokia.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>