package/gnuradio: fix gr-pager option

Since a very long time (at least version 3.5.1 in 2011 and
https://github.com/gnuradio/gnuradio/commit/accb9f2fe8fd8f6a1e114adac5b15304b0e0012d),
gr-pager option is named ENABLE_GR_PAGER, not ENABLE_PAGER

Signed-off-by: Fabrice Fontaine <fontaine.fabrice@gmail.com>
Signed-off-by: Yann E. MORIN <yann.morin.1998@free.fr>

package/gnuradio/gnuradio.mk

@@ -130,9 +130,9 @@ GNURADIO_CONF_OPTS += -DENABLE_PYTHON=OFF
 endif
 
 ifeq ($(BR2_PACKAGE_GNURADIO_PAGER),y)
-GNURADIO_CONF_OPTS += -DENABLE_PAGER=ON
+GNURADIO_CONF_OPTS += -DENABLE_GR_PAGER=ON
 else
-GNURADIO_CONF_OPTS += -DENABLE_PAGER=OFF
+GNURADIO_CONF_OPTS += -DENABLE_GR_PAGER=OFF
 endif
 
 ifeq ($(BR2_PACKAGE_GNURADIO_TRELLIS),y)