ARM: dts: exynos: Remove console argument from bootargs

Remove the "console=ttySAC..." argument from DTSes having a proper
stdout-path property.  To make the code functionally equivalent, add the
serial port baud rate and parity.

Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Reviewed-by: Sylwester Nawrocki <s.nawrocki@samsung.com>