trusty: Fix return value of trusty_init()

The value used to signal failure is 0. It is needed to return a different
value on success.

Change-Id: I2186aa7dfbfc825bfe7b3d5ae3c4de7af10ee44f
Signed-off-by: Antonio Nino Diaz <antonio.ninodiaz@arm.com>

services/spd/trusty/trusty.c

@@ -322,7 +322,7 @@ static int32_t trusty_init(void)
 	fpregs_context_restore(get_fpregs_ctx(cm_get_context(NON_SECURE)));
 	cm_set_next_eret_context(NON_SECURE);
 
-	return 0;
+	return 1;
 }
 
 static void trusty_cpu_suspend(uint32_t off)