Move the implementation of bcm_host to vc_host

bcm_host_init -> vc_open - this should be called from gralloc_open or
hwcomposer_open

graphics_get_display_size -> vc_dispmanx_display_get_size
implemented vc_vchi_dispmanx.c. A more natural home as it's just a
wrapper around vc_dispmanx_display_get_info
update headers
Remove libgralloc bcm_host from libgralloc
switch to vc_host header
Move tests to a common location
Add New Dispmanx tests
move to right directory
Interim commit
Interim commit for gralloc
Remove redundant defines from cflags
Add Videocore logging build property