ARM: dts: meson: meson8: add the CPU OPP table

The values are taken from Amlogic's 3.10 kernel sources. Their sources
have a "meson8m2_n200_2G.dtd" which defines a different voltage table:
- 0.86V for 96MHz
- (values in between omitted)
- 1.14V for 1.992GHz

The reason for this is simply the hardware design because the voltage
regulator on this board is has a minimum output of 0.86V and a maximum
output of 1.14V. The recommended settings are added with this patch
instead of using the values that are only valid for one board.

Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Signed-off-by: Kevin Hilman <khilman@baylibre.com>