ggml-hexagon: add HTP unary ops for ABS and LOG (#27786)

Add HVX-accelerated implementations for GGML_OP_LOG and
GGML_UNARY_OP_ABS on the HTP backend.

- Register HTP_OP_UNARY_ABS and HTP_OP_UNARY_LOG in op_remap_to_htp()
- Add ABS and LOG to ggml_backend_hexagon_device_supports_op()
- Implement hvx_abs_f32_aa() in hvx-arith.h using hvx_vec_abs_f32()
- Implement hvx_log_f32_aa() in hvx-log.h using hvx_vec_log_f32()
- Add abs_f32() and log_f32() row-wise dispatch in unary-ops.c
- Define tiled and non-tiled task functions via DEFINE_UNARY_TASK and
  DEFINE_UNARY_TILED_TASK macros
- Route HTP_OP_UNARY_ABS and HTP_OP_UNARY_LOG through execute_op()
  in main.c

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

@@ -777,6 +777,8 @@ static int execute_op(struct htp_ops_context * octx) {
         case HTP_OP_UNARY_NEG:
         case HTP_OP_UNARY_EXP:
         case HTP_OP_UNARY_TANH:
+        case HTP_OP_UNARY_ABS:
+        case HTP_OP_UNARY_LOG:
         case HTP_OP_L2_NORM:
             return op_unary(octx);