i965: Initialize the SampleMap{2,4,8}x variables

i965: Initialize the SampleMap{2,4,8}x variables

with values specific to Intel hardware.

V2: Define and use gen6_get_sample_map() function to initialize
    the variables.

V3: Change the function name to gen6_set_sample_maps() and use
    memcpy() to fill in the data.

Signed-off-by: Anuj Phogat <anuj.phogat@gmail.com>
Reviewed-by: Jordan Justen <jordan.l.justen@intel.com>