xtensa: fsf: drop nonexistent GPIO32 support

The toolchain for xtensa FSF core never supported GPIO32, drop it on the
linux side too.

Reported-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
Acked-by: Baruch Siach <baruch@tkos.co.il>