programmer: Smoothen register_par_master API

It was impossible to register a const struct par_master that would
point to dynamically allocated `data`. Fix that so that we won't
have to create more mutable globals.

Change-Id: I95bc92f6c54c5bcdac1c522ca87054aaffed0f40
Signed-off-by: Anastasia Klimchuk <aklm@chromium.org>
Original-Reviewed-on: https://review.coreboot.org/c/flashrom/+/54169
Original-Reviewed-by: Edward O'Callaghan <quasisec@chromium.org>
Reviewed-on: https://review.coreboot.org/c/flashrom-stable/+/72201
Reviewed-by: Nico Huber <nico.h@gmx.de>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
diff --git a/serprog.c b/serprog.c
index 2626be1..ab559bb 100644
--- a/serprog.c
+++ b/serprog.c
@@ -706,7 +706,7 @@
 	if (serprog_buses_supported & BUS_SPI)
 		register_spi_master(&spi_master_serprog, NULL);
 	if (serprog_buses_supported & BUS_NONSPI)
-		register_par_master(&par_master_serprog, serprog_buses_supported & BUS_NONSPI);
+		register_par_master(&par_master_serprog, serprog_buses_supported & BUS_NONSPI, NULL);
 	return 0;
 }