lib: sbi: Detect extensions from the ISA string in DT

Enable access to some extensions through menvcfg and show them in "Boot
HART ISA Extensions" if they are present in the device tree.

Signed-off-by: Yong-Xuan Wang <yongxuan.wang@sifive.com>
Reviewed-by: Anup Patel <anup@brainfault.org>

include/sbi/sbi_hart.h

@@ -47,6 +47,12 @@ enum sbi_hart_extensions {
 	SBI_HART_EXT_SMCNTRPMF,
 	/** Hart has Xandespmu extension */
 	SBI_HART_EXT_XANDESPMU,
+	/** Hart has Zicboz extension */
+	SBI_HART_EXT_ZICBOZ,
+	/** Hart has Zicbom extension */
+	SBI_HART_EXT_ZICBOM,
+	/** Hart has Svpbmt extension */
+	SBI_HART_EXT_SVPBMT,
 
 	/** Maximum index of Hart extension */
 	SBI_HART_EXT_MAX,