Change in coreboot[master]: sb/intel/common: Refactor _PRT generation to support GSI-based tables

[Furquan Shaikh (Code Review)]

Attention is currently required from: Nico Huber, Tim Wawrzynczak, Angel Pons, Patrick Rudolph.
Furquan Shaikh has posted comments on this change. ( https://review.coreboot.org/c/coreboot/+/50857 )

Change subject: sb/intel/common: Refactor _PRT generation to support GSI-based tables
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Patch Set 19: Code-Review+1

(5 comments)

Commit Message:

https://review.coreboot.org/c/coreboot/+/50857/comment/c0ecf1d7_a8551ed7 
PS19, Line 10: insteade
instead

File src/southbridge/intel/common/acpi_pirq_gen.h:

https://review.coreboot.org/c/coreboot/+/50857/comment/c41475fd_d9798ae5 
PS19, Line 33: The type of IRQ
             :  * (GSI or PIRQ) comes from `pirq_map_type`.
             :  *
This seems like it went back to an older patchset?

https://review.coreboot.org/c/coreboot/+/50857/comment/a9f2db26_c1d8c5ac 
PS19, Line 39: pack
path?

File src/southbridge/intel/common/acpi_pirq_gen.c:

https://review.coreboot.org/c/coreboot/+/50857/comment/1c984cfd_36926d5a 
PS15, Line 15: /*
             : 		 * The reason for subtracting PCI_INT_A from the pin given is
             : 		 * that PCI defines pins as 1-4, and _PRT uses 0-3.
             : 		 */
Was this intentionally dropped? Or just a bad rebase?

File src/southbridge/intel/common/rcba_pirq.c:

https://review.coreboot.org/c/coreboot/+/50857/comment/6c114fdf_fa400940 
PS19, Line 74: int_idx
nit: This is used in just one place i.e. printk. Probably can be dropped?