clk: samsung: Pass actual CPU clock registers base to CPU_CLK()

clk: samsung: Pass actual CPU clock registers base to CPU_CLK()

The documentation for struct exynos_cpuclk says .ctrl_base field should
contain the controller base address. There are two different problems
with that:

1. All Exynos clock drivers are actually passing CPU_SRC register offset
   via CPU_CLK() macro, which in turn gets assigned to mentioned
   .ctrl_base field. Because CPU_SRC register usually already has 0x200
   offset from controller's base, all other register offsets in
   clk-cpu.c (like DIVs and MUXes) are specified as offsets from CPU_SRC
   offset, and not from controller's base. That makes things confusing
   and inconsistent with register offsets provided in Exynos clock
   drivers, also breaking the contract for .ctrl_base field as described
   in struct exynos_cpuclk doc.

2. Furthermore, some Exynos chips have an additional offset for the
   start of CPU clock registers block (inside of the CMU). There might
   be different reasons for that, e.g.:

   - The CMU contains clocks for two different CPUs (like in Exynos5420)
   - The CMU contains also non-CPU clocks as well (like in Exynos4)
   - The CPU CMU exists as a dedicated hardware block in the SoC layout,
     but is modelled as a part of bigger CMU in the driver (like in case
     of Exynos3250)

   That means the .ctrl_base field is actually not a controller's base,
   but instead it's a start address of the CPU clock registers inside of
   the CMU.

Rework all register offsets in clk-cpu.c to be actual offsets from the
CPU clock register block start, and fix offsets provided to CPU_CLK()
macro in all Exynos clock drivers. Also clarify the .ctrl_base field
documentation and rename it to just .base, because it doesn't really
contain the CMU base.

No functional change.

Signed-off-by: Sam Protsenko <semen.protsenko@linaro.org>
Link: https://lore.kernel.org/r/20240224202053.25313-8-semen.protsenko@linaro.org
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>