ARM: dts: Correct camera pinctrl nodes for Exynos4x12 SoCs

Add separate nodes for the CAMCLK pin and turn off pull-up on camera
ports A, B. The video bus pins and the clock output (CAMCLK) pin need
separate nodes since full camera port is not used in some configurations,
e.g. for MIPI CSI-2 bus only CAMCLK is required and data/clock signal
use separate dedicated pins.

Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Reviewed-by: Tomasz Figa <t.figa@samsung.com>
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>