Correct space added for pmp-writable schema (#197)

Author: MuhammadHammad001

riscv_config/schemas/schema_isa.yaml

@@ -153,7 +153,7 @@ hart_schema:
           type: integer
           max: [64]
           default: 16
-	pmp-writable:
+        pmp-writable:
           type: integer
           max: [64]
           default: 7