drm/bridge: samsung-dsim: allow configuring PLL_M and PLL_S offsets

drm/bridge: samsung-dsim: allow configuring PLL_M and PLL_S offsets

Currently, PLL_P offset of DSIM_PLLCTRL is configurable in the driver
data, while PLL_M and PLL_S offsets are hardcoded as 4-bit and 1-bit
offsets respectively, but Exynos7870's DSIM have them at 3-bit and 0-bit
offsets as per downstream kernel sources.

In order to support both, move both offset values to the driver data
struct and define it for every driver compatible. Reference the values
from there instead, in functions wherever required.

Signed-off-by: Kaustabh Chakraborty <kauschluss@disroot.org>
Signed-off-by: Inki Dae <inki.dae@samsung.com>