fix: [rocm/rocm_smi_lib] header cleanup Remove non-unified headers

Cleans up individual gpu metric APIs which will be implemented according to 'unified-headers' standards

Code changes related to the following:
  * 'rsmi_dev_metrics_' APIs
  * Functional tests
  * Examples

Change-Id: I7d562a95889361ee6f8f7588f8a790f42c8eb262
Signed-off-by: Oliveira, Daniel <daniel.oliveira@amd.com>

src/rocm_smi_gpu_metrics.cc

@@ -2680,7 +2680,6 @@ rsmi_status_t Device::dev_read_gpu_metrics_header_data()
   LOG_TRACE(ostrstream);
 
   // Check if/when metrics table needs to be refreshed.
-  auto now_ts = actual_timestamp_in_secs();
   if ((!m_gpu_metrics_header.m_structure_size)    ||
       (!m_gpu_metrics_header.m_format_revision)   ||
       (!m_gpu_metrics_header.m_content_revision)) {