arm64: dts: apple: t8012: Add cpufreq nodes

Add cpufreq nodes for Apple A10 SoC. There is a transparent hardware
big.LITTLE switcher in this SoC. Spoof E-core p-state frequencies such
that CPU capacity does not appear to change when switching between core
types.

Signed-off-by: Nick Chan <towinchenmi@gmail.com>
Reviewed-by: Neal Gompa <neal@gompa.dev>
Signed-off-by: Sven Peter <sven@svenpeter.dev>