mmc: renesas_sdhi: Fix rounding errors

mmc: renesas_sdhi: Fix rounding errors

Due to clk rounding errors on RZ/G2L platforms, it selects a clock source
with a lower clock rate compared to a higher one.
For eg: The rounding error (533333333 Hz / 4 * 4 = 533333332 Hz < 5333333
33 Hz) selects a clk source of 400 MHz instead of 533.333333 MHz.

This patch fixes this issue by adding a margin of (1/1024) higher to
the clock rate.

Signed-off-by: Biju Das <biju.das.jz@bp.renesas.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Tested-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Tested-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Fixes: bb6d3fa98a41 ("clk: renesas: rcar-gen3: Switch to new SD clock handling")
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20220928110755.849275-1-biju.das.jz@bp.renesas.com
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>