[U-Boot] is it mandatory for SPL to support DM

SPL has a foot-print constraint, so fully switching a particular subsystem like SPI or SPI Flash to DM would increase the size of it.

Possible areas to look at are (assume SPL_DM supported) 1) platdata 2) implement board or platform specific spl device driver which bypassed the actual framework ex: spl_spi_sunxi.c

Do we have any other solutions? or any arguments on above step 2?

Jagan.