The max size was determined by looking at the ARCH of the cpu. This really
comes from the ip configuration when generated. Add `max-xfer-size`
property to the devicetree.
Signed-off-by: Ryan McClelland <ryanmcclelland@meta.com>
Introduce DesignWare ARC Data Fusion IP Subsystem(DFSS) SPI
driver for ARC boards, i.e. EMSDP, which uses DW SPI to controll
SPI-Flash and DFSS SPI to connect external devices. Both drivers
share most source code, but DFSS uses ARC auxiliary registers.
Move FIFO depth setting to device tree.
Signed-off-by: Siyuan Cheng <siyuanc@synopsys.com>