uboot-phytec

arm: sunxi: Move spl spi sunxi code to mach-sunxi

This SUNXI variant SPL SPI code doesn't use either SPI or
SPL_FLASG subsystems due to size constraints and also placing
this code in drivers/mtd/spi will unnecessary build SPI_FLASH
code(if defined) which never required, hence moved to arch area.

And also renamed the file according to kconfig which resembles
proper name.

Signed-off-by: Jagan Teki <jagan@amarulasolutions.com>