The commit a3e19973 made the LED working again on HP Mini 210 but
with a wrong polarity.  This patch fixes the polarity for this
machine, and also introduce a new model string "hp-inv-led".

Bugzilla: https://bugzilla.novell.com/show_bug.cgi?id=772923

Cc: <stable@vger.kernel.org> [v3.3+]
Signed-off-by: NTakashi Iwai <tiwai@suse.de>