In order to setup the DSI clock, let's make the unused VCLK2 clock path
configuration via CCF.

The nocache option is removed from following clocks:
- vclk2_sel
- vclk2_input
- vclk2_div
- vclk2
- vclk_div1
- vclk2_div2_en
- vclk2_div4_en
- vclk2_div6_en
- vclk2_div12_en
- vclk2_div2
- vclk2_div4
- vclk2_div6
- vclk2_div12
- cts_encl_sel

vclk2 and vclk2_div uses the newly introduced vclk regmap driver
to handle the enable and reset bits.

In order to set a rate on cts_encl via the vclk2 clock path,
the NO_REPARENT flag is set on cts_encl_sel & vclk2_sel in order
to keep CCF from selection a parent.
The parents of cts_encl_sel & vclk2_sel are expected to be defined
in DT or manually set by the display driver at some point.

The following clock scheme is to be used for DSI:

xtal
\_ gp0_pll_dco
   \_ gp0_pll
      |- vclk2_sel
      |  \_ vclk2_input
      |     \_ vclk2_div
      |        \_ vclk2
      |           \_ vclk2_div1
      |              \_ cts_encl_sel
      |                 \_ cts_encl	-> to VPU LCD Encoder
      |- mipi_dsi_pxclk_sel
      \_ mipi_dsi_pxclk_div
         \_ mipi_dsi_pxclk		-> to DSI controller

The mipi_dsi_pxclk_div is set as bypass with a single /1 entry in div_table
in order to use the same GP0 for mipi_dsi_pxclk and vclk2_input.

The SET_RATE_PARENT is only set on the mipi_dsi_pxclk_sel clock so the
DSI bitclock is the reference base clock to calculate the vclk2_div value
when pixel clock is set on the cts_encl endpoint.
Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org>
Link: https://lore.kernel.org/r/20240403-amlogic-v6-4-upstream-dsi-ccf-vim3-v12-3-99ecdfdc87fc@linaro.orgSigned-off-by: Jerome Brunet <jbrunet@baylibre.com>