configure: prevent build of linuxgpiod with libgpiod v2

The API in libgpiod v2 have changed, and current driver code for
linuxgpiod does not build anymore.

Prevent building the current driver linuxgpiod with the new
library.

Change-Id: Ie673db786dc50ae18a263d2c0a2b46b106866450
Signed-off-by: Antonio Borneo <borneo.antonio@gmail.com>
Reviewed-on: https://review.openocd.org/c/openocd/+/8185
Reviewed-by: Michael Heimpold <michaheimpold@gmail.com>
Tested-by: jenkins
Reviewed-by: Tomas Vanek <vanekt@fbl.cz>

configure.ac

@@ -669,7 +669,7 @@ PKG_CHECK_MODULES([LIBFTDI], [libftdi1], [
 	PKG_CHECK_MODULES([LIBFTDI], [libftdi], [use_libftdi=yes], [use_libftdi=no])
 ])
 
-PKG_CHECK_MODULES([LIBGPIOD], [libgpiod], [use_libgpiod=yes], [use_libgpiod=no])
+PKG_CHECK_MODULES([LIBGPIOD], [libgpiod < 2.0], [use_libgpiod=yes], [use_libgpiod=no])
 
 PKG_CHECK_MODULES([LIBJAYLINK], [libjaylink >= 0.2],
 	[use_libjaylink=yes], [use_libjaylink=no])