clk: renesas: rcar-gen3: Switch to new SD clock handling

The old SD handling code was huge and could not handle all the details
which showed up on R-Car Gen3 SoCs meanwhile. It is time to switch to
another design. Have SDnH a separate clock, use the existing divider
clocks and move the errata handling from the clock driver to the SDHI
driver where it belongs.

This patch removes the old SD handling code and switch to the new one.
This updates the SDHI driver at the same time. Because the SDHI driver
can only communicate with the clock driver via clk_set_rate(), I don't
see an alternative to this flag-day-approach, so we cross subsystems
here.

The patch sadly looks messy for the CPG lib, but it is basically a huge
chunk of code removed and smaller chunks added. It looks much better
when you just view the resulting source file.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Acked-by: Ulf Hansson <ulf.hansson@linaro.org> # For MMC
Link: https://lore.kernel.org/r/20211110191610.5664-6-wsa+renesas@sang-engineering.com
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>

clk: renesas: rcar-gen3: Add dummy SDnH clock

Currently, SDnH is handled together with SDn. This caused lots of
problems, so we want SDnH as a separate clock. Introduce a dummy SDnH
type here which creates a fixed-factor clock with factor 1. That allows
us to convert the per-SoC CPG drivers while keeping the old behaviour
for now. A later patch then will add the proper functionality.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Link: https://lore.kernel.org/r/20211110191610.5664-2-wsa+renesas@sang-engineering.com
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>

clk: renesas: cpg-lib: Move RPC clock registration to the library

We want to reuse this code for V3U soon. Because its RPCCKCR register is
at a different offset, the moved functions do not use the base register
as an argument anymore but the RPCCKCR register itself. Verified that an
Eagle board with R-Car V3M still works.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Link: https://lore.kernel.org/r/20211006085836.42155-2-wsa+renesas@sang-engineering.com
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>

clk: renesas: rcar-gen3: Factor out CPG library

R-Car V3U has a CPG different enough to not be a generic Gen3 CPG but
similar enough to reuse code. Introduce a new CPG library, factor out
the SD clock handling and hook it to the generic Gen3 CPG driver so we
have an equal state. V3U will make use of it in the next patch then.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Link: https://lore.kernel.org/r/20201227174202.40834-4-wsa+renesas@sang-engineering.com
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>