lib: sbi: Add sbi_domain_root_add_memregion() API

We should allow platform support to add more root memory regions
before domains are finalized. This will help platform support to
protect critical M-mode only resources.

This patch adds sbi_domain_root_add_memregion() API for above
described purpose.

Signed-off-by: Anup Patel <anup.patel@wdc.com>
Reviewed-by: Xiang W <wxjstz@126.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>

include/sbi/sbi_domain.h

@@ -170,6 +170,14 @@ void sbi_domain_dump_all(const char *suffix);
 int sbi_domain_register(struct sbi_domain *dom,
 			const struct sbi_hartmask *assign_mask);
 
+/**
+ * Add a memory region to the root domain
+ * @param reg pointer to the memory region to be added
+ *
+ * @return 0 on success and negative error code on failure
+ */
+int sbi_domain_root_add_memregion(const struct sbi_domain_memregion *reg);
+
 /** Finalize domain tables and startup non-root domains */
 int sbi_domain_finalize(struct sbi_scratch *scratch, u32 cold_hartid);