arch/arm/src/imxrt: Fixes for clean eDMA driver build with Scatter/Gather enabled.
arch/arm/src/imxrt: Fixes for clean eDMA driver build with Scatter/Gather disabled.
arch/arm/src/imxrt: Add flags to DMA configuration to control transfer setup. Remove some user interfaces that are inconsistent with modular design.
arch/arm/src/imxrt: Update DMA channel interrupt handler.
arch/arm/src/imxrt: Add implementation of eDMA imxrt_dmach_start().
arch/arm/src/imxrt: Add implementation of eDMA imxrt_dmach_setup().
arch/arm/src/imxrt: Add eDMA imxrt_tcd_chanlink().
arch/arm/src/imxrt: Add eDMA imxrt_dmach_getcount; free allocated TCDs automatically when the DMA completes or is aborted.