meson: Generalise libflashrom product to link as static or dyn

Allow the user to specify if they would like a static archive or a DSO
produced for libflashrom by way of the flag e.g. `-Ddefault_library=static`.

Signed-off-by: Daniel Campello <campello@chromium.org>
Change-Id: I77e5c298163979a0222270b3ac5d03542e5618f7
Original-Reviewed-on: https://review.coreboot.org/c/flashrom/+/51616
Original-Reviewed-by: Edward O'Callaghan <quasisec@chromium.org>
Reviewed-on: https://review.coreboot.org/c/flashrom-stable/+/71767
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Nico Huber <nico.h@gmx.de>
diff --git a/meson.build b/meson.build
index 86015ff..6a9981f 100644
--- a/meson.build
+++ b/meson.build
@@ -357,7 +357,7 @@
 
 mapfile = 'libflashrom.map'
 vflag = '-Wl,--version-script,@0@/@1@'.format(meson.current_source_dir(), mapfile)
-flashrom = shared_library(
+flashrom = library(
   'flashrom',
   sources : [
     srcs,