platform/x86/intel/vsec: Remove a useless mutex

platform/x86/intel/vsec: Remove a useless mutex

ida_alloc()/ida_free() don't need any mutex, so remove this one.

It was introduced by commit 9a90ea7d3784 ("platform/x86/intel/vsec: Use
mutex for ida_alloc() and ida_free()").

Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Link: https://lore.kernel.org/r/ccc08a262304f7f8c2e435349f0f714ebf9acfcd.1730563031.git.christophe.jaillet@wanadoo.fr
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>