Bump master version to 1.2.
Bump master version to 1.2.

1.1.x series will be maintained on Release_v1.1 branch.

Signed-off-by: Yang Rong <78759e37dc7114caed18f74e7515c5cb519dbf6d@intel.com>

wdv4758h/beignet,wdv4758h/beignet,wdv4758h/beignet,wdv4758h/beignet,wdv4758h/beignet