gf180mcu I/O Library missing Site definition and incorrect pad class in lef file

[dhaentz1]

Expected Behavior

Add the correct site definition "GF_IO_Site" and "GF_COR_Site" to the current *.lef file of the gf180mcu I/O library. The Site must be defined before it can be referenced within the pad cells.

The padd class need also be modified to AREAIO for each pad cell.

Actual Behavior

The current *.lef file of the I/O library does not contain the Site definition "GF_IO_SITE" and "GF_COR_Site"and therefor automatic IO cell placement does not work correctly.

Steps to Reproduce the Problem

See the attached patch file to see all required modifications

/cc @proppy
/cc @chaufe
gf180mcu_fd_io.lef.patch