ggml-hexagon: add PAD op HVX kernel (#23078)

* ggml-hexagon: add PAD op HVX kernel

Implements GGML_OP_PAD on the Hexagon HTP backend using HVX vectorized
kernels. Supports zero-padding and circular padding across all 4 tensor
dimensions.

* hex-ggml: remove duplicate op cases (merge conflict)

* hex-pad: fix editorconfig checks and macro alignment

---------

Co-authored-by: Max Krasnyansky <maxk@qti.qualcomm.com>

ggml/src/ggml-hexagon/htp/main.c

@@ -595,6 +595,9 @@ static int execute_op(struct htp_ops_context * octx) {
         case HTP_OP_SOLVE_TRI:
             return op_solve_tri(octx);
 
+        case HTP_OP_PAD:
+            return op_pad(octx);
+
         case HTP_OP_GATED_DELTA_NET:
             return op_gated_delta_net(octx);