php7: fix linking to libpcre

PHP comes with a bundled version of libpcre which is then statically
linked. However, we already depend on the packaged library, so we
can reduce the footprint when linking to it dynamically.
This saves around 200-300 kB (this depends on other configuration).

Signed-off-by: Michael Heimpold <mhei@heimpold.de>

lang/php7/Makefile

@@ -7,7 +7,7 @@ include $(TOPDIR)/rules.mk
 
 PKG_NAME:=php
 PKG_VERSION:=7.2.2
-PKG_RELEASE:=1
+PKG_RELEASE:=2
 
 PKG_MAINTAINER:=Michael Heimpold <mhei@heimpold.de>
 
@@ -167,6 +167,7 @@ CONFIGURE_ARGS+= \
 	--with-config-file-scan-dir=/etc/php7 \
 	--disable-short-tags \
 	\
+	--with-pcre-regex="$(STAGING_DIR)/usr" \
 	--with-zlib="$(STAGING_DIR)/usr" \
 	  --with-zlib-dir="$(STAGING_DIR)/usr"