[U-Boot] Remove atmel_dataflash_spi.c

[Jagan Teki]

Hi Stelian/Alison,

Need some inputs here, since atmel dataflash driver is already
up-streamed on flash side at drivers/mtd/spi/sf_dataflash.c then what
is the point of using drivers/spi/atmel_dataflash_spi.c at spi side.

Are they identically same? can't we use sf_dataflash for common
dataflash operations like what we does in atmel_dataflash_spi?

Thanks!

Jagan.
-- 
Jagan Teki
Free Software Engineer | www.openedev.com
U-Boot, Linux | Upstream Maintainer
Hyderabad, India.