package/gstreamer1/gst1-vaapi: fix tests config option

Fixes:
output/build/gst1-vaapi-1.18.5/meson.build:1:0: ERROR: Unknown options: "test"

(WARNING for now, but will be an error in meson 0.60.0).

Signed-off-by: James Hilliard <james.hilliard1@gmail.com>
Reviewed-by: Peter Seiderer <ps.report@gmx.net>
Signed-off-by: Arnout Vandecappelle (Essensium/Mind) <arnout@mind.be>
(cherry picked from commit d352ae712198799012acd2176214fbe62e2383a1)
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

package/gstreamer1/gst1-vaapi/gst1-vaapi.mk

@@ -24,7 +24,7 @@ GST1_VAAPI_CONF_OPTS += \
 	-Dwith_wayland=no \
 	-Dwith_egl=no \
 	-Dexamples=disabled \
-	-Dtest=disabled \
+	-Dtests=disabled \
 	-Ddoc=disabled
 
 ifeq ($(BR2_PACKAGE_GST1_VAAPI_ENCODERS),y)