igc: Make the const read-only array supported_sizes static

Don't populate the const read-only array supported_sizes on the
stack at run time, instead make it static.

Signed-off-by: Colin Ian King <colin.i.king@gmail.com>
Reviewed-by: Alexander Lobakin <aleksander.lobakin@intel.com>
Reviewed-by: Vitaly Lifshits <vitaly.lifshits@intel.com&gt;>
Link: https://patch.msgid.link/20250618135408.1784120-1-colin.i.king@gmail.com


Signed-off-by: Jakub Kicinski <kuba@kernel.org>