i965: Import tables enumerating the set of validated L3 configurations.

i965: Import tables enumerating the set of validated L3 configurations.

It should be possible to use additional L3 configurations other than
the ones listed in the tables of validated allocations ("BSpec »
3D-Media-GPGPU Engine » L3 Cache and URB [IVB+] » L3 Cache and URB [*]
» L3 Allocation and Programming"), but it seems sensible for now to
hard-code the tables in order to stick to the hardware docs.  Instead
of setting up the arbitrary L3 partitioning given as input, the
closest validated L3 configuration will be looked up in these tables
and used to program the hardware.

The included tables should work for Gen7-9.  Note that the quantities
are specified in ways rather than in KB, this is because the L3
control registers expect the value in ways, and because by doing that
we can re-use a single table for all GT variants of the same
generation (and in the case of IVB/HSW and CHV/SKL across different
generations) which generally have different L3 way sizes but allow the
same combinations of way allocations.

v2: Use slice count from the devinfo structure instead of the gt
    number to implement get_l3_way_size().

Reviewed-by: Samuel Iglesias Gonsálvez <siglesias@igalia.com>
Acked-by: Kenneth Graunke <kenneth@whitecape.org>
Reviewed-by: Kristian Høgsberg  <krh@bitplanet.net>