ARM: OMAP: Make plat/omap-pm.h local to mach-omap2

We must move this for ARM common zImage support.

Note that neither drivers/media/rc/ir-rx51.c or
drivers/media/platform/omap3isp/ispvideo.c need
to include omap-pm.h, so this patch removes the
include for those files.

Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Cc: Mauro Carvalho Chehab <mchehab@infradead.org>
Cc: Timo Kokkonen <timo.t.kokkonen@iki.fi>
Cc: linux-media@vger.kernel.org
Signed-off-by: Tony Lindgren <tony@atomide.com>