freetype: pkconfig needs to use sysroot as prefix

Can't set --prefix=$SYSROOT_PREFIX/usr as this creates sysroot-within-sysroot, so
patch it into freetype2.pc.

Once freetype2 is using the correct prefix we can drop the CFLAGS workaround from lcdd.

packages/addons/service/lcdd/package.mk

@@ -31,7 +31,6 @@ PKG_CONFIGURE_OPTS_TARGET="--with-ft-prefix=$SYSROOT_PREFIX/usr \
 
 pre_configure_target() {
   CFLAGS="$CFLAGS -O3"
-  CFLAGS="$CFLAGS -I$SYSROOT_PREFIX/usr/include/freetype2"
 }
 
 addon() {

packages/print/freetype/package.mk

@@ -27,5 +27,7 @@ pre_configure_target() {
 }
 
 post_makeinstall_target() {
+  sed -e "s#prefix=/usr#prefix=${SYSROOT_PREFIX}/usr#" -i "${SYSROOT_PREFIX}/usr/lib/pkgconfig/freetype2.pc"
+
   cp -P "${PKG_BUILD}/.${TARGET_NAME}/freetype-config" "${SYSROOT_PREFIX}/usr/bin"
 }