igb: fix typos in comments

igb: fix typos in comments

Fix spelling errors in code comments:
 - e1000_nvm.c: 'likley' -> 'likely'
 - e1000_mac.c: 'auto-negotitation' -> 'auto-negotiation'
 - e1000_mbx.h: 'exra' -> 'extra'
 - e1000_defines.h: 'Aserted' -> 'Asserted'

Signed-off-by: Maximilian Pezzullo <maximilianpezzullo@gmail.com>
Reviewed-by: Aleksandr Loktionov <aleksandr.loktionov@intel.com>
Reviewed-by: Joe Damato <joe@dama.to>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>
Link: https://patch.msgid.link/20260609213559.178657-15-anthony.l.nguyen@intel.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>