clk: meson: axg-audio: remove useless defines

Defining the number of each input type is no longer necessary since
we are not using the clk-input hack anymore

Fixes: 282420ee

 ("clk: meson: axg-audio: migrate to the new parent description method")
Acked-by: Neil Armstrong <narmstrong@baylibre.com>
Signed-off-by: Jerome Brunet <jbrunet@baylibre.com>