drm: bridge: dw-hdmi: Detect AHB audio DMA using correct register

Bit 0 in CONFIG1_ID tells whether the IP core uses an AHB slave
interface for control. The correct way to identify AHB audio DMA support
is through bit 1 in CONFIG3_ID.

Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Reviewed-by: Jose Abreu <joabreu@synopsys.com>
Signed-off-by: Archit Taneja <architt@codeaurora.org>
Link: http://patchwork.freedesktop.org/patch/msgid/20170117082910.27023-15-laurent.pinchart+renesas@ideasonboard.com