staging: vc04_services: Move global variables tracking allocated pages

The variables tracking allocated pages fragments in vchiq_arm.c
can be easily moved to struct vchiq_drv_mgmt instead of being global.
This helps us to drop the non-essential global variables in the vchiq
interface.

No functional changes intended in this patch.

Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Umang Jain <umang.jain@ideasonboard.com>
Reviewed-by: Stefan Wahren <wahrenst@gmx.net>
Link: https://lore.kernel.org/r/20240412075743.60712-7-umang.jain@ideasonboard.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>