Update TargetInfo.cpp

[cdevadas]

Enabling implicit kernel argument support for HIP.

[cdevadas]

Enabled the implicit kernel argument area for HIP as well. With this attribute enabled from clang, compiler backend adds the implicit arguments (48-Bytes) at the end of the actual user argument area. Since the implicit kernargs are inserted at the tail of the actual arguments, there is no change in the offset generated for the user parameters. Hence there won't be any break in the existing HIP tests with this commit. For the consumers of the implicit kernarg area, HIP runtime library should be modified to accommodate the implicit kernargs at runtime.