spl: replace CONFIG_SPL_SPI_* with CONFIG_SF_DEFAULT_*

spl: replace CONFIG_SPL_SPI_* with CONFIG_SF_DEFAULT_*

Currently, CONFIG_SPL_SPI_* #defines are used for controlling SPI boot in
SPL. These #defines do not allow the user to select SPI mode for the SPI flash
(there's no CONFIG_SPL_SPI_MODE, so the SPI mode is hardcoded in
spi_spl_load.c), and duplicate information already provided by
CONFIG_SF_DEFAULT_* #defines.

Kill CONFIG_SPL_SPI_*, and use CONFIG_SF_DEFAULT_* instead.

Cc: Tom Rini <[email protected]>
Cc: Marek Vasut <[email protected]>
Cc: Sudhakar Rajashekhara <[email protected]>
Cc: Lokesh Vutla <[email protected]>
Cc: Vitaly Andrianov <[email protected]>
Cc: Lars Poeschel <[email protected]>
Cc: Bo Shen <[email protected]>
Cc: Hannes Petermaier <[email protected]>
Cc: Michal Simek <[email protected]>
Acked-by: Marek Vasut <[email protected]>
Signed-off-by: Nikita Kiryanov <[email protected]>
Reviewed-by: Jagannadha Sutradharudu Teki <[email protected]>