spi25: Introduce spi_simple_write_cmd()

spi_simple_write_cmd() executes WREN plus a single byte write and polls
WIP afterwards. It's used to replace current spi_erase_chip_*() imple-
mentations.

Change-Id: Ib244356fa471e15863b52e6037899d19113cb4a9
Signed-off-by: Nico Huber <nico.h@gmx.de>
Reviewed-on: https://review.coreboot.org/22382
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: David Hendricks <david.hendricks@gmail.com>
2 files changed