Strip pango libraries on the target

Use the predefined INSTALL_STAGING_OPT and INSTALL_TARGET_OPT
behaviour of Makefile.autotools.in, so that installation on the target
is done using install-strip.

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>

package/pango/pango.mk

@@ -9,8 +9,6 @@ PANGO_SITE = http://ftp.gnome.org/pub/GNOME/sources/pango/1.19
 PANGO_AUTORECONF = YES
 PANGO_INSTALL_STAGING = YES
 PANGO_INSTALL_TARGET = YES
-PANGO_INSTALL_STAGING_OPT = DESTDIR=$(STAGING_DIR) install
-PANGO_INSTALL_TARGET_OPT = DESTDIR=$(TARGET_DIR) install
 
 PANGO_CONF_ENV = ac_cv_func_posix_getpwuid_r=yes glib_cv_stack_grows=no \
 		glib_cv_uscore=no ac_cv_func_strtod=yes \