bitbang: Extend register_spi_bitbang_master() API with spi data

This allows the users of register_spi_bitbang_master() API to pass
their spi data into the API, and then the data can go further, into
register_spi_master() API.

flashrom-stable: Removed unnecessary if.

Change-Id: I13e83ae74dbc3a3e79c84d1463683d360ff47bc0
Signed-off-by: Anastasia Klimchuk <aklm@chromium.org>
Original-Reviewed-on: https://review.coreboot.org/c/flashrom/+/54990
Original-Reviewed-by: Edward O'Callaghan <quasisec@chromium.org>
Reviewed-on: https://review.coreboot.org/c/flashrom-stable/+/73267
Reviewed-by: Nico Huber <nico.h@gmx.de>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
8 files changed