alsa-mixer: Add path for Headset Microphone

In kernel 3.10, some devices will have the "Headset Microphone" name
to indicate that the mic is part of a mic + headphone combo, i e, a headset.

src/modules/alsa/mixer/paths/analog-input-headset-mic.conf

@@ -0,0 +1,99 @@
+# This file is part of PulseAudio.
+#
+# PulseAudio is free software; you can redistribute it and/or modify
+# it under the terms of the GNU Lesser General Public License as
+# published by the Free Software Foundation; either version 2.1 of the
+# License, or (at your option) any later version.
+#
+# PulseAudio is distributed in the hope that it will be useful, but
+# WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+# General Public License for more details.
+#
+# You should have received a copy of the GNU Lesser General Public License
+# along with PulseAudio; if not, write to the Free Software Foundation,
+# Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
+
+; For devices where a 'Headset Mic' or 'Headset Mic Boost' element exists
+;
+; See analog-output.conf.common for an explanation on the directives
+
+[General]
+priority = 87
+name = analog-input-microphone-headset
+
+[Jack Headset Mic]
+required-any = any
+
+[Jack Headset Mic Phantom]
+state.plugged = unknown
+state.unplugged = unknown
+required-any = any
+
+[Element Headset Mic Boost]
+required-any = any
+switch = select
+volume = merge
+override-map.1 = all
+override-map.2 = all-left,all-right
+
+[Element Headset Mic]
+required-any = any
+switch = mute
+volume = merge
+override-map.1 = all
+override-map.2 = all-left,all-right
+
+[Element Capture]
+switch = mute
+volume = merge
+override-map.1 = all
+override-map.2 = all-left,all-right
+
+[Element Input Source]
+enumeration = select
+
+[Option Input Source:Headset Mic]
+name = Headset Microphone
+required-any = any
+
+[Element Capture Source]
+enumeration = select
+
+[Option Capture Source:Headset Mic]
+name = Headset Microphone
+required-any = any
+
+[Element Front Mic]
+switch = off
+volume = off
+
+[Element Internal Mic]
+switch = off
+volume = off
+
+[Element Rear Mic]
+switch = off
+volume = off
+
+[Element Dock Mic]
+switch = off
+volume = off
+
+[Element Dock Mic Boost]
+switch = off
+volume = off
+
+[Element Internal Mic Boost]
+switch = off
+volume = off
+
+[Element Front Mic Boost]
+switch = off
+volume = off
+
+[Element Rear Mic Boost]
+switch = off
+volume = off
+
+.include analog-input-mic.conf.common