drm/bridge: cdns-dsi: Replace deprecated UNIVERSAL_DEV_PM_OPS()

drm/bridge: cdns-dsi: Replace deprecated UNIVERSAL_DEV_PM_OPS()

The deprecated UNIVERSAL_DEV_PM_OPS() macro uses the provided callbacks
for both runtime PM and system sleep. This causes the DSI clocks to be
disabled twice: once during runtime suspend and again during system
suspend, resulting in a WARN message from the clock framework when
attempting to disable already-disabled clocks.

[   84.384540] clk:231:5 already disabled
[   84.388314] WARNING: CPU: 2 PID: 531 at /drivers/clk/clk.c:1181 clk_core_disable+0xa4/0xac
...
[   84.579183] Call trace:
[   84.581624]  clk_core_disable+0xa4/0xac
[   84.585457]  clk_disable+0x30/0x4c
[   84.588857]  cdns_dsi_suspend+0x20/0x58 [cdns_dsi]
[   84.593651]  pm_generic_suspend+0x2c/0x44
[   84.597661]  ti_sci_pd_suspend+0xbc/0x15c
[   84.601670]  dpm_run_callback+0x8c/0x14c
[   84.605588]  __device_suspend+0x1a0/0x56c
[   84.609594]  dpm_suspend+0x17c/0x21c
[   84.613165]  dpm_suspend_start+0xa0/0xa8
[   84.617083]  suspend_devices_and_enter+0x12c/0x634
[   84.621872]  pm_suspend+0x1fc/0x368

To address this issue, replace UNIVERSAL_DEV_PM_OPS() with
RUNTIME_PM_OPS(). Bridge and panel drivers should only deal with runtime
PM, as the DRM framework manages system-wide power transitions through
the bridge enable() and disable() hooks.

Link: https://lore.kernel.org/all/fbde0659-78f3-46e4-98cf-d832f765a18b@ideasonboard.com/
Cc: stable@vger.kernel.org # 6.1.x
Fixes: e19233955d9e ("drm/bridge: Add Cadence DSI driver")
Reviewed-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
Signed-off-by: Vitor Soares <vitor.soares@toradex.com>
Reviewed-by: Luca Ceresoli <luca.ceresoli@bootlin.com>
Link: https://patch.msgid.link/20260505134705.188661-2-ivitro@gmail.com
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>