clk: bcm2835: Switch to clk_divider.determine_rate

clk: bcm2835: Switch to clk_divider.determine_rate

.determine_rate is meant to replace .round_rate in CCF in the future.
Switch over to .determine_rate now that clk_divider_ops has gained
support for that.

Cc: Marek Szyprowski <m.szyprowski@samsung.com>
Cc: Nicolas Saenz Julienne <nsaenz@kernel.org>
Cc: Florian Fainelli <f.fainelli@gmail.com>
Cc: Ray Jui <rjui@broadcom.com>
Cc: Scott Branden <sbranden@broadcom.com>
Cc: bcm-kernel-feedback-list@broadcom.com
Cc: linux-rpi-kernel@lists.infradead.org
Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Link: https://lore.kernel.org/r/20210702225145.2643303-4-martin.blumenstingl@googlemail.com
Tested-by: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>