Use IO type and module type enums

[vipangul]

Problem solved by the commit

Defines IO type enums and uses it to define PLIO or GMIO IO type. Also module_type has been used at applicable places.

Bug / issue (if any) fixed, which PR introduced the bug, how it was discovered

NA

How problem was solved, alternative solutions (if any) and why they were rejected

code readability enhancement.

Risks (if any) associated the changes in the commit

Minimal as it just adds enums in place of int variable types.

What has been tested and how, request additional testing if necessary

Documentation impact (if any)