clk: mediatek: mt7988: replace clock ID with upstream linux

Replace infracfg clk ID with upstream linux version.

The same format is used here with the factor first, then mux and then
gates.

To correctly reference the gates in clk_gate function, define the
gates_offs value in clk_tree now that they are at an offset from mux and
factor.

Drop any comment that reference the clock ID as we now have a 1:1 match
with upstream kernel linux.

Signed-off-by: Christian Marangi <ansuelsmth@gmail.com>