[mlir][tosa] Fix indexing in TosaToTensor

Changed the indexing used in the extractOp from one that is intended for
0d tensors to one that is intended for 1d tensors.

Author: Shay Kleiman

mlir/lib/Conversion/TosaToTensor/TosaToTensor.cpp

@@ -362,7 +362,8 @@ class PadConverter : public OpConversionPattern<tosa::PadOp> {
     // Setup the default constantAttr.
 
     Value padConstant = rewriter.createOrFold<tensor::ExtractOp>(
-        loc, padOp.getPadConst(), ValueRange({}));
+      loc, padOp.getPadConst(),
+      ValueRange({rewriter.create<arith::ConstantIndexOp>(loc, 0)}));
 
     if (!padConstant) {
       return rewriter.notifyMatchFailure(