phy: exynos-mipi-video: correct cam0 sysreg property name for exynos7870

Fix the cam0 sysreg property name (samsung,cam0-sysreg), which has been
erroneously declared as samsung,cam-sysreg. This follows the same name
used in Exynos5433 PHY.

Fixes: 543f5e31 ("phy: exynos-mipi-video: introduce support for exynos7870")
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: Kaustabh Chakraborty <kauschluss@disroot.org>
Link: https://lore.kernel.org/r/20250710-exynos7870-mipi-phy-fix-v2-1-5cf50d69c9d7@disroot.org


Signed-off-by: Vinod Koul <vkoul@kernel.org>