x86_64 libs are located in ANDROID_PLATFORM_ROOT_PATH/usr/lib64
not in ANDROID_PLATFORM_ROOT_PATH/usr/lib .

Fixes: QTBUG-47672
Change-Id: Ia1f74f7c2a30b276b95fd0e7dcf8370d739e3c41
Reviewed-by: Eskil Abrahamsen Blomfeldt <eskil.abrahamsen-blomfeldt@qt.io>
(cherry picked from commit 43763e27

)
Reviewed-by: Jani Heikkinen <jani.heikkinen@qt.io>