clk: actions: Fix UART clock dividers on Owl S500 SoC

clk: actions: Fix UART clock dividers on Owl S500 SoC

Use correct divider registers for the Actions Semi Owl S500 SoC's UART
clocks.

Fixes: ed6b4795ece4 ("clk: actions: Add clock driver for S500 SoC")
Signed-off-by: Cristian Ciocaltea <cristian.ciocaltea@gmail.com>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Link: https://lore.kernel.org/r/4714d05982b19ac5fec2ed74f54be42d8238e392.1623354574.git.cristian.ciocaltea@gmail.com
Signed-off-by: Stephen Boyd <sboyd@kernel.org>