clk: call the clock init() callback before any other ops callback

Some clocks may need to initialize things, whatever it is, before
being able to properly operate. Move the .init() call before any
other callback, such recalc_rate() or get_phase(), so the clock
is properly setup before being used.

Signed-off-by: Jerome Brunet <jbrunet@baylibre.com>
Signed-off-by: Michael Turquette <mturquette@baylibre.com>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>