regulator: wm8994: Use PROBE_FORCE_SYNCHRONOUS

Restore synchronous probing for wm8994 regulators because otherwise the
sound device is never initialized on Exynos5250-based Arndale board.

Fixes: 259b93b21a9f ("regulator: Set PROBE_PREFER_ASYNCHRONOUS for drivers that existed in 4.14")
Signed-off-by: Marek Szyprowski <[e-mail]>
Acked-by: Charles Keepax <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Mark Brown <[e-mail]>

drivers/regulator/wm8994-regulator.c

···
 	.probe = wm8994_ldo_probe,
 	.driver		= {
 		.name	= "wm8994-ldo",
-		.probe_type = PROBE_PREFER_ASYNCHRONOUS,
+		.probe_type = PROBE_FORCE_SYNCHRONOUS,
 	},
 };