memory_bus: Turn flashbase into a par_master member `rom_base`

Get rid of the global `flashbase`. Treat overrides for the `rom_base`
similar to `max_rom_decode`: Gather the information in `internal_data`
and then pass it to register_par_master().

Change-Id: Ib9ed7234a849fe3550200fd602226d0036da15f0
Signed-off-by: Nico Huber <nico.h@gmx.de>
Reviewed-on: https://review.sourcearcade.org/c/flashprog/+/436
diff --git a/serprog.c b/serprog.c
index 257562a..e1d33ed 100644
--- a/serprog.c
+++ b/serprog.c
@@ -766,7 +766,7 @@
 	if (serprog_buses_supported & BUS_SPI)
 		register_spi_master(&spi_master_serprog, 0, NULL);
 	if (serprog_buses_supported & BUS_NONSPI)
-		register_par_master(&par_master_serprog, serprog_buses_supported & BUS_NONSPI, 0, NULL);
+		register_par_master(&par_master_serprog, serprog_buses_supported & BUS_NONSPI, 0, 0, NULL);
 	return 0;
 
 init_err_cleanup_exit: