clk: add table lookup to mux

Add a table lookup feature to the mux clock. Also allow arbitrary masks
instead of the width. This will be used by some clocks on Tegra114. Also
adapt the tegra periph clk because it uses struct clk_mux directly.

Signed-off-by: Peter De Schrijver <pdeschrijver@nvidia.com>
Tested-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Mike Turquette <mturquette@linaro.org>