arm64: dts: lg: Fix SP805 clocks

The SP805 DT binding requires two clocks to be specified, but the two
LG platform DTs currently only specify one clock.

In practice, Linux would pick a clock named "apb_pclk" for the bus
clock, and the Linux (and U-Boot) SP805 driver would use the first clock
to derive the actual watchdog counter frequency.

Since currently both are the very same clock, we can just double the
clock reference, and add the correct clock-names, to match the binding.

Link: https://lore.kernel.org/r/20200907121831.242281-6-andre.przywara@arm.com


Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Acked-by: Chanho Min <chanho.min@lge.com>
Signed-off-by: Olof Johansson <olof@lixom.net>