[M] Change in coreboot[master]: acpi: Add SPCR table

[Tim Wawrzynczak (Code Review)]

Attention is currently required from: Arthur Heymans, Benjamin Doron, Lance Zhao, Nico Huber.

Tim Wawrzynczak has posted comments on this change. ( https://review.coreboot.org/c/coreboot/+/75685?usp=email )

Change subject: acpi: Add SPCR table
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Patch Set 5: Code-Review+2

(2 comments)

File src/acpi/acpi.c:

https://review.coreboot.org/c/coreboot/+/75685/comment/0ebb4ab6_5d36cbf2 :
PS3, Line 1870: 	/* TODO: provide callback for IRQ on non standard ports*/
> > Would it be bad not to use an IRQ at all? […]

that should work for the earlycon, it looks like Linux doesn't use interrupts for the early console

File src/include/acpi/acpi.h:

https://review.coreboot.org/c/coreboot/+/75685/comment/097c0dbd_274ba245 :
PS5, Line 1336: #define RISCV_PLIC_COMPATIBLE_INTERRUPT (1 << 4)
minor nit: I won't hold up the patch, but would be nice to align the right sides