arm64: dts: apple: t8103: Add AUDIO_P parent to the SIO_ADMA power domain

The SIO_ADMA is a power domain of the Audio DMA Controller. In addition
to it, the AUDIO_P domain must be on for the controller's MMIO registers
to be accessible.

On t600x and t8112, AUDIO_P is a parent of SIO_ADMA. On t8103, it isn't
so, at least as far as Apple's firmware goes. To make our life easier,
add the parent-child relationship on t8103 also.

Signed-off-by: Martin Povišer <povik+lin@cutebit.org>
Signed-off-by: Janne Grunau <j@jannau.net>
Acked-by: Marc Zyngier <maz@kernel.org>
Signed-off-by: Hector Martin <marcan@marcan.st>