[Intel-gfx] [PATCH] drm/i915: bump platform_mask to u64

[Chris Wilson]

Quoting Lucas De Marchi (2019-03-15 00:13:31)
> With Elkhart Lake being added to the platforms we are almost on the edge
> of platforms that fits on this 32 bits mask. So bump it to 64 bits to
> have room for new ones.
> 
> Cc: José Roberto de Souza <jose.souza at intel.com>
> Signed-off-by: Lucas De Marchi <lucas.demarchi at intel.com>

Since platform_mask exists as an optimisation for code size, it'll be
useful to track the impact of changes.
-Chris