The datasheet says that it should reply to rdid (as done by probe_spi_rdid()) with 0xC2 0x20 0x18 which is matching flashrom's definition of "MX25L12805(D)".
Which it does. However, in the hope of getting automatic clean identification, I’ve shifted to probe_spi_rems, which it seems to respond to. Unfortunately, this still isn’t enough for automatic identification.
Tony