Add patch for realtek codec in Lenovo B50-70 that fixes inverted
internal microphone channel.
Device IdeaPad Y410P has the same PCI SSID as Lenovo B50-70,
but first one is about fix the noise and it didn't seem help in a
later kernel version.
So I replaced IdeaPad Y410P device description with B50-70 and apply
inverted microphone fix.

Bugzilla: https://bugs.launchpad.net/ubuntu/+source/alsa-driver/+bug/1524215Signed-off-by: Michał Wadowski <wadosm@gmail.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>