drivers: dma: Refactor drivers to use shared init priority

Refactors all of the DMA drivers to use a shared driver class
initialization priority configuration, CONFIG_DMA_INIT_PRIORITY, to
allow configuring DMA drivers separately from other devices. This is
similar to other driver classes like I2C and SPI.

Most drivers previously used CONFIG_KERNEL_INIT_PRIORITY_DEFAULT or
CONFIG_KERNEL_INIT_PRIORITY_DEVICE, therefore the default for this new
option is the lower of the two, which means earlier initialization.

Signed-off-by: Maureen Helm <maureen.helm@intel.com>
12 files changed