Add support for dma-channel-mask so that only the specified channels
are used. This helps to reserve some channels for the firmware.

This was initially achieved by limiting the channel number to 31 in
the driver and adjusting the register address to skip channel0 which
was reserved for a firmware. This is wrong and does not align with
the hardware.

Now, with this change, the driver can align more to the actual hardware
which has 32 channels. But this implies that there will be a break in the
ABI and the device tree need to be updated along with this change for the
driver to pickup the right interrupt corresponding to the channel
Reviewed-by: Jon Hunter <jonathanh@nvidia.com>
Link: https://lore.kernel.org/all/Y2EFoG1H9YpfxRjs@orome/Signed-off-by: Akhil R <akhilrajeev@nvidia.com>
Link: https://lore.kernel.org/r/20221110171748.40304-4-akhilrajeev@nvidia.comSigned-off-by: Vinod Koul <vkoul@kernel.org>