package/armadillo: don't override dependencies

Don't override ARMADILLO_DEPENDENCIES in a conditional

Signed-off-by: Fabrice Fontaine <fontaine.fabrice@gmail.com>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>
(cherry picked from commit 05fb75e495d0b3f636de7558a14309f1e6061bfb)
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

package/armadillo/armadillo.mk

@@ -17,7 +17,7 @@ ARMADILLO_CONF_OPTS = -DDETECT_HDF5=false
 ARMADILLO_CONF_OPTS += -DBLAS_FOUND=ON
 ifeq ($(BR2_PACKAGE_ARMADILLO_OPENBLAS),y)
 ARMADILLO_CONF_OPTS += -DBLAS_LIBRARIES=-lopenblas
-ARMADILLO_DEPENDENCIES = openblas
+ARMADILLO_DEPENDENCIES += openblas
 else
 # Since BR2_PACKAGE_LAPACK is selected in this case, the dependency on it is
 # added below.