drm/i915: Invert if/else ladder for frequency read

Continue converting the driver to the convention of last version first,
extending it to the future platforms. Now, any GRAPHICS_VER >= 11 will
be handled by the first branch.

With the new ranges it's easier to see what platform a branch started to
be taken. Besides the >= 11 change, the branch taken for GRAPHICS_VER == 10
is also different, but currently there is no such platform in i915.

Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com>
Reviewed-by: Matt Roper <matthew.d.roper@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220908-if-ladder-v2-1-7a7b15545c93@intel.com