mfd: atmel-hlcdc: Fetch LVDS PLL clock for LVDS display

mfd: atmel-hlcdc: Fetch LVDS PLL clock for LVDS display

The XLCDC IP supports parallel RGB, MIPI DSI and LVDS Display.
The LCD Generic clock (sys_clk) is used for Parallel RGB and MIPI
displays, while the LVDS PLL clock (lvds_pll_clk) is used for LVDS
displays.Since both the clocks cannot co-exist together in the DT
for a given display, this patch tries sys_clk first (RGB/MIPI),
fallback to lvds_pll_clk (LVDS).

Signed-off-by: Manikandan Muralidharan <manikandan.m@microchip.com>
Signed-off-by: Dharma Balasubiramani <dharma.b@microchip.com>
Link: https://patch.msgid.link/20260223101920.284697-2-manikandan.m@microchip.com
Signed-off-by: Lee Jones <lee@kernel.org>