Comment 1 for bug 1257268

In order to support mic_mute key, we need changes in both BIOS and dell-wmi as below:

 1. BIOS needs to issue BIOS event 0x150 in WMI
 2. BIOS needs to include an entry in SMBSIOS
 3. dell-wmi.c needs to map the entry

1 and 2 should be true for dell systems with mic mute hotkey; however, a kernel patch is required for 3.