ARM: dts: exynos4212-tab3: add samsung,invert-vclk flag to fimd

[ Upstream commit eab4f56d ]

After more investigation, I've found that it's not the panel driver
config that needs to be modified to invert the data polarity, but
the FIMD config.

Add the missing invert-vclk option that is required to get the display
to work correctly.

Fixes: ee37a457

 ("ARM: dts: exynos: Add Samsung Galaxy Tab 3 8.0 boards")
Signed-off-by: Artur Weber <aweber.kernel@gmail.com>
Link: https://lore.kernel.org/r/20240105-tab3-display-fixes-v2-1-904d1207bf6f@gmail.com
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>