lib: sbi: Detect support of debug triggers

Detect if debug triggers, sdtrig extension, is supported
by the CPU. The support is detected by access traps and
ISA string parsing.

Signed-off-by: Himanshu Chauhan <hchauhan@ventanamicro.com>
Reviewed-by: Anup Patel <anup@brainfault.org>

include/sbi/sbi_hart.h

@@ -53,6 +53,8 @@ enum sbi_hart_extensions {
 	SBI_HART_EXT_ZICBOM,
 	/** Hart has Svpbmt extension */
 	SBI_HART_EXT_SVPBMT,
+	/** Hart has debug trigger extension */
+	SBI_HART_EXT_SDTRIG,
 
 	/** Maximum index of Hart extension */
 	SBI_HART_EXT_MAX,