[Trusty SRU] Fix acpi brightness interface on HP dv6

[Alex Hung]

SRU Justification: 

Impact: The acpi_video0 interface on HP dv6 laptop fails to work after 
	_OSI("Windows 2012") is true in kernel 3.13

Fix:	Add this system into blacklist so _OSI("Windows 2012") will be 
	always false

Note: This is not needed for 3.16 kernel as native backlight is used instead

BugLink: http://bugs.launchpad.net/bugs/1416940