Android: Fix x86_64 linking

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>

mkspecs/common/android-base-tail.conf

@@ -69,6 +69,7 @@ QMAKE_LIBDIR_OPENGL     =
 
 QMAKE_LINK_SHLIB        = $$QMAKE_LINK
 QMAKE_LFLAGS            = --sysroot=$$ANDROID_PLATFORM_ROOT_PATH
+equals(ANDROID_TARGET_ARCH, x86_64) QMAKE_LFLAGS += -L$$ANDROID_PLATFORM_ROOT_PATH/usr/lib64
 QMAKE_LFLAGS_APP        = -Wl,--no-undefined -Wl,-z,noexecstack -shared
 QMAKE_LFLAGS_SHLIB      = -Wl,--no-undefined -Wl,-z,noexecstack -shared
 QMAKE_LFLAGS_PLUGIN     = $$QMAKE_LFLAGS_SHLIB