drm: bridge/dw_hdmi: remove ratio support from ACR code

We never set the ratio for CTS/N calculation for the audio clock
regenerator (ACR) to anything but 100, so this adds pointless
complexity.  Should we support pixel repetition, we should update the
CTS/N calculation code to use those parameters or the actual TMDS clock
rate instead of a ratio.

Tested-by: Fabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>