clk: Aspeed: Setup video engine clocking

Add eclk mux and clock divider table. Also change the video engine reset
to the correct clock; it was previously on the video capture but needs
to be on the video engine clock.

Signed-off-by: Eddie James <eajames@linux.ibm.com>
Reviewed-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>