package/mariadb: provide native compiled mariadb_config

- overwrite cross-compiled mariadb_config executable (used from the
  mysql_config script) by a native/host compiled one

Fixes (qt5base configure):

  Trying source 0 (type mysqlConfig) of library mysql ...
  + .../host/aarch64-buildroot-linux-gnu/sysroot/usr/bin/mysql_config --version
  > .../host/aarch64-buildroot-linux-gnu/sysroot/usr/bin/mysql_config: line 100: \
    .../host/aarch64-buildroot-linux-gnu/sysroot/usr/bin/mariadb_config: cannot execute binary file: Exec format error

  with

  $ file host/aarch64-buildroot-linux-gnu/sysroot/usr/bin/mariadb_config
  host/aarch64-buildroot-linux-gnu/sysroot/usr/bin/mariadb_config: ELF 64-bit LSB pie executable, ARM aarch64, version 1 (SYSV), dynamically linked, interpreter /lib/ld-linux-aarch64.so.1, for GNU/Linux 5.10.0, with debug_info, not stripped

Reported-by: Scott Bartolett <SBartolett@thorlabs.com>
Signed-off-by: Peter Seiderer <ps.report@gmx.net>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>

package/mariadb/mariadb.mk

@@ -135,5 +135,13 @@ endef
 
 MARIADB_POST_INSTALL_TARGET_HOOKS += MARIADB_POST_INSTALL
 
+# overwrite cross-compiled mariadb_config executable by an native one
+define MARIADB_POST_STAGING_INSTALL
+	$(HOSTCC) -I$(@D)/libmariadb/include \
+		-o $(STAGING_DIR)/usr/bin/mariadb_config \
+		$(@D)/libmariadb/mariadb_config/mariadb_config.c
+endef
+MARIADB_POST_INSTALL_STAGING_HOOKS += MARIADB_POST_STAGING_INSTALL
+
 $(eval $(cmake-package))
 $(eval $(host-cmake-package))