Remove mhpmcounter CSR access tests
Created by: halfdan-dolva
Removed mhpmcounter CSR access tests as they require all 29 mhpmcounters configured but the 40s has none. Removed perf_counters_instructions test as it only tests mhpmcounters.
Signed-off-by: Halfdan Bechmann halfdan.bechmann@silabs.com