UPDATE 2-Boeing to submit 737 MAX software upgrade 'in the coming weeks'

WASHINGTON/SEATTLE, April 1 (Reuters) - Boeing Co plans to submit a proposed software enhancement package for the grounded 737 MAX in "the coming weeks" after the company had previously said it planned to deliver the fix for government approval by last week.The company on Monday confirmed a statement from the Federal Aviation Administration that it would submit the upgrade later than previously announced."We are working to demonstrate that we have identified and appropriately addressed all certi