remove enableFirmwareLogs

This config parameter is no longer needed since we always want it to be
true.

Bug: 28277924
Test: compile, unit test
Test: device turns on and could connect to wifi
Test: With wifi verbose logging disabled, do dumpsys wifi and verify there
are no driver dumps.
Test: With wifi verbose logging enabled, do dumpsys wifi and verify there are
driver dumps.
Change-Id: I045e5e7d368f9e748ce27b3c6e668a755b7e9c31