clk: gemini: Remove an unused field in struct clk_gemini_pci

In "struct clk_gemini_pci", the 'rate' field is unused.

Remove it.

Found with cppcheck, unusedStructMember.

Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Link: https://lore.kernel.org/r/556770c7701868f9f1c0569674903bee3eff30cb.1713015940.git.christophe.jaillet@wanadoo.fr
Signed-off-by: Stephen Boyd <sboyd@kernel.org>