drm: bridge: samsung-dsim: Dynamically configure DPHY timing

The DPHY timings are currently hard coded. Since the input
clock can be variable, the phy timings need to be variable
too.  To facilitate this, we need to cache the hs_clock
based on what is generated from the PLL.

The phy_mipi_dphy_get_default_config_for_hsclk function
configures the DPHY timings in pico-seconds, and a small macro
converts those timings into clock cycles based on the hs_clk.

Signed-off-by: Adam Ford <aford173@gmail.com>
Signed-off-by: Lucas Stach <l.stach@pengutronix.de>
Tested-by: Chen-Yu Tsai <wenst@chromium.org>
Tested-by: Frieder Schrempf <frieder.schrempf@kontron.de>
Reviewed-by: Frieder Schrempf <frieder.schrempf@kontron.de>
Tested-by: Michael Walle <michael@walle.cc>
Tested-by: Marek Szyprowski <m.szyprowski@samsung.com>
Reviewed-by: Jagan Teki <jagan@amarulasolutions.com>
Tested-by: Jagan Teki <jagan@amarulasolutions.com> # imx8mm-icore
Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20230526030559.326566-6-aford173@gmail.com