fix build for targets without threads

package/libpthread/Makefile

@@ -34,9 +34,11 @@ INSTALL_STYLE:=		manual
 libpthread-install:
 ifneq ($(ADK_TARGET_LIB_MUSL),y)
 ifneq ($(ADK_TARGET_USE_STATIC_LIBS),y)
+ifneq ($(ADK_TARGET_WITHOUT_THREADS),y)
 	${INSTALL_DIR} ${IDIR_LIBPTHREAD}/$(ADK_TARGET_LIBC_PATH)
 	${CP} ${STAGING_TARGET_DIR}/lib/libpthread*.so* ${IDIR_LIBPTHREAD}/$(ADK_TARGET_LIBC_PATH)
 endif
 endif
+endif
 
 include ${ADK_TOPDIR}/mk/pkg-bottom.mk