clk: st: clkgen-pll: remove unused variable of struct clkgen_pll

ODF field within the struct clkgen_pll is never used by the driver
and can thus be removed.

Signed-off-by: Alain Volmat <avolmat@me.com>
Reviewed-by: Patrice Chotard <patrice.chotard@foss.st.com>
Link: https://lore.kernel.org/r/20210331201632.24530-2-avolmat@me.com


Signed-off-by: Stephen Boyd <sboyd@kernel.org>