Fix building with meson, again

Change-Id: Iea40da587729f3975a8901d3933e7567805242c5
Signed-off-by: Angel Pons <th3fanbus@gmail.com>
Reviewed-on: https://review.coreboot.org/c/flashrom/+/38659
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Frans Hendriks <fhendriks@eltan.com>
Reviewed-by: David Hendricks <david.hendricks@gmail.com>
Reviewed-by: Edward O'Callaghan <quasisec@chromium.org>
Reviewed-by: Carl-Daniel Hailfinger <c-d.hailfinger.devel.2006@gmx.net>

meson_options.txt

@@ -33,3 +33,4 @@ option('config_satamv', type : 'boolean', value : true, description : 'Marvell S
 option('config_satasii', type : 'boolean', value : true, description : 'SiI SATA controllers')
 option('config_serprog', type : 'boolean', value : true, description : 'serprog')
 option('config_usbblaster_spi', type : 'boolean', value : true, description : 'Altera USB-Blaster dongles')
+option('config_stlinkv3_spi', type : 'boolean', value : true, description : 'STMicroelectronics STLINK-V3')