grep: bump to version 2.9

Bump grep to version 2.9
Also make it build after busybox if it's enabled, we prefer full-blown
utilities.

Signed-off-by: Gustavo Zacarias <gustavo@zacarias.com.ar>
Signed-off-by: Peter Korsgaard <jacmet@sunsite.dk>

package/grep/grep.mk

@@ -4,7 +4,7 @@
 #
 #############################################################
 
-GREP_VERSION = 2.7
+GREP_VERSION = 2.9
 GREP_SITE = $(BR2_GNU_MIRROR)/grep
 GREP_CONF_OPT = --disable-perl-regexp --without-included-regex
 GREP_DEPENDENCIES = $(if $(BR2_NEEDS_GETTEXT_IF_LOCALE),gettext libintl)
@@ -15,4 +15,9 @@ GREP_CONF_ENV += LIBS=-liconv
 GREP_DEPENDENCIES += libiconv
 endif
 
+# Full grep preferred over busybox grep
+ifeq ($(BR2_PACKAGE_BUSYBOX),y)
+GREP_DEPENDENCIES += busybox
+endif
+
 $(eval $(call AUTOTARGETS))