arm64: dts: meson: remove CPU opps below 1GHz for G12B boards

Amlogic G12B devices experience CPU stalls and random board wedges when
the system idles and CPU cores clock down to lower opp points. Recent
vendor kernels include a change to remove 100-250MHz and other distro
sources also remove the 500/667MHz points. Unless all 100-667Mhz opps
are removed or the CPU governor forced to performance stalls are still
observed, so let's remove them to improve stability and uptime.

Fixes: b96d4e92

 ("arm64: dts: meson-g12b: support a311d and s922x cpu operating points")
Signed-off-by: Christian Hewitt <christianshewitt@gmail.com>
Reviewed-by: Neil Armstrong <narmstrong@baylibre.com>
Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
Link: https://lore.kernel.org/r/20220210100638.19130-2-christianshewitt@gmail.com