package/sdl2_ttf: disable builtin freetype2

Disable builtin freetype2 which is enabled by default since bump to
version 2.0.18 in commit f4da031a77f200515bcc5b2e0fe665a7b4f2a780 and
https://github.com/libsdl-org/SDL_ttf/commit/834ec54127dc9c2a12928f5fe32cf110ec4c7a7f

Signed-off-by: Fabrice Fontaine <fontaine.fabrice@gmail.com>
Signed-off-by: Arnout Vandecappelle (Essensium/Mind) <arnout@mind.be>

package/sdl2_ttf/sdl2_ttf.mk

@@ -11,6 +11,7 @@ SDL2_TTF_LICENSE = Zlib
 SDL2_TTF_LICENSE_FILES = COPYING.txt
 SDL2_TTF_INSTALL_STAGING = YES
 SDL2_TTF_DEPENDENCIES = sdl2 freetype host-pkgconf
+SDL2_TTF_CONF_OPTS = --disable-freetype-builtin
 
 # x-includes and x-libraries must be set for cross-compiling
 # By default x_includes and x_libraries contains unsafe paths.