ARM: socfpga: dts: Remove hard coded clock-frequency property

The timers and uart can get their clock frequencies using the common clock
driver.

Reviewed-by: Steffen Trumtrar <s.trumtrar@pengutronix.de>
Signed-off-by: Dinh Nguyen <dinguyen@altera.com>

diff --cc arch/arm/boot/dts/socfpga.dtsi
Simple merge

diff --cc arch/arm/boot/dts/socfpga_arria5.dtsi
Simple merge

diff --cc arch/arm/boot/dts/socfpga_cyclone5.dtsi
Simple merge