spi25.c: Factor out rdid_get_ids() and compare_id()

This is in preparation for implementing a cache for the
probe results of RDID and REMS (3&4-byte variant) commands.
The intention is to make probing of SPI rom's slightly
faster, a few 10's of ms dependant upon the spi master used.

BUG=b:15656443
BRANCH=none
TEST=builds

Change-Id: I1556e97a7c70425069e3d1dc0d5daf0aeec4e7bf
Signed-off-by: Edward O'Callaghan <quasisec@google.com>
Reviewed-on: https://review.coreboot.org/c/flashrom/+/41398
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Angel Pons <th3fanbus@gmail.com>
Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>
1 file changed