cmd/sbi: display new extensions

The SBI specification v2.0-rc2 defines new extensions:

* Nested Acceleration Extension (NACL)
* Steal Time Accounting (STA)

Allow the sbi command to display these.

Add missing implementation IDs.

Signed-off-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>
Reviewed-by: Leo Yu-Chi Liang <ycliang@andestech.com>
diff --git a/arch/riscv/include/asm/sbi.h b/arch/riscv/include/asm/sbi.h
index 7693699..009a268 100644
--- a/arch/riscv/include/asm/sbi.h
+++ b/arch/riscv/include/asm/sbi.h
@@ -31,6 +31,8 @@
 	SBI_EXT_DBCN = 0x4442434E,
 	SBI_EXT_SUSP = 0x53555350,
 	SBI_EXT_CPPC = 0x43505043,
+	SBI_EXT_NACL = 0x4E41434C,
+	SBI_EXT_STA = 0x535441,
 };
 
 enum sbi_ext_base_fid {