vc4: Compute the proper end address of the relocated command lists.

vc4: Compute the proper end address of the relocated command lists.

render_cl_size/bin_cl_size includes relocations, while the hardware buffer
doesn't.  If you don't emit a HALT packet, the command parser continues
until the end register's value.  We can't allow executing unvalidated
buffer contents (and it's actually harmful in the render lists Mesa is
emitting, since VC4_PACKET_STORE_MS_TILE_BUFFER_AND_EOF doesn't trigger a
halt).