drivers/spi/spi_flash: Pass in flash structure to fill in probe

Instead of making all SPI drivers allocate space for a spi_flash
structure and fill it in, udpate the API to allow callers to pass in a
spi_flash structure that can be filled by the flash drivers as
required. This also cleans up the interface so that the callers can
maintain and free the space for spi_flash structure as required.

BUG=b:38330715

Change-Id: If6f1b403731466525c4690777d9b32ce778eb563
Signed-off-by: Furquan Shaikh <furquan@chromium.org>
Reviewed-on: https://review.coreboot.org/19705
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Aaron Durbin <adurbin@chromium.org>
25 files changed