The sram allocations for the cx23887 differ slightly from the cx23885.
This patch modifies the cx23887 specific sram memory map to reflect this.
As a result, interrupts and DMA handling have also been enabled in
cx23885_start_dma() for 887 specific boards.

ATSC streaming is now available on cx23885 and cx23887 bridges.
Signed-off-by: Steven Toth <stoth@hauppauge.com>
Signed-off-by: Michael Krufky <mkrufky@linuxtv.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>