target/arm_dpm: report vector catch as breakpoint

Commit 4afa32ece1 ("aarch64: unify armv7-a and armv8
debug entry decoding")
probably unintentionally removed DSCR_ENTRY_VECT_CATCH from
reported debug entry reasons. Note the discrepancy between
'case DSCR_ENTRY_BKPT_INSTR:' and its comment.

Hitting vector catch was reported as DBG_REASON_UNDEFINED.
DBG_REASON_UNDEFINED disturbed hwthread/gdb cooperation and
gdb reported the wrong thread as stopped by SIGTRAP.

Revert to the original functionality and report vector
catch as a breakpoint.

Change-Id: I12e938182cff8f633decba340000cfbb7b112ae3
Signed-off-by: Tomas Vanek <vanekt@fbl.cz>
Reviewed-on: https://review.openocd.org/c/openocd/+/9209
Tested-by: jenkins
Reviewed-by: Antonio Borneo <borneo.antonio@gmail.com>

src/target/arm_dpm.c

@@ -1064,7 +1064,8 @@ void arm_dpm_report_dscr(struct arm_dpm *dpm, uint32_t dscr)
 		target->debug_reason = DBG_REASON_DBGRQ;
 		break;
 	case DSCR_ENTRY_BREAKPOINT:	/* HW breakpoint */
-	case DSCR_ENTRY_BKPT_INSTR:	/* vector catch */
+	case DSCR_ENTRY_BKPT_INSTR: /* SW BKPT */
+	case DSCR_ENTRY_VECT_CATCH:	/* vector catch */
 		target->debug_reason = DBG_REASON_BREAKPOINT;
 		break;
 	case DSCR_ENTRY_IMPRECISE_WATCHPT:	/* asynch watchpoint */