Short answer = no
Long answer = noooooooooo
XD Sorry, been wathcing Vicar of Dibley. =P
DX is a hardware enabled feature, and so in order for DX 11.2 to work, you need hardware that is designed to handle DX 11.2. Backwards compatibility isnt a problem, as if you had a card that could handle DX 11.2, it could also ahndle all other previous versions of DX.
I dont think there are actually any DX 11.2 enabled cards out yet, although Im sure it wont be long. to my knowledge the only things that will support DX 11.2 so far is the Xbox One and Windows 8.1 (But again, Windows 8.1 needs the hardware to go with it).
But I wouldnt worry too much about this. Games campanies appreciate the fact that most of the gaming market at the minute are using either DX10 or 11. Seeing as you currently cannot get hold of DX 11.2 hardware yet, they will want to manufacture games that most people can play. Theres alot that can be said about the subject.
Bottom line is, no, your card does not support it, and no amount of updates will make it support it, but it makes no difference at the minute anyway. =)