Change in coreboot[master]: console: Add IO port serial logging

[Raul Rangel (Code Review)]

Attention is currently required from: Alexey Buyanov, Jason Glenesk, Nico Huber, Marshall Dawson, Julius Werner, Nikolai Vyssotski, Fred Reitberger, Felix Held.
Raul Rangel has posted comments on this change. ( https://review.coreboot.org/c/coreboot/+/61311 )

Change subject: console: Add IO port serial logging
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Patch Set 5:

(4 comments)

File src/arch/x86/include/arch/io.h:

https://review.coreboot.org/c/coreboot/+/61311/comment/a3708577_151dc03e 
PS5, Line 8: 0x5f535452ul
This is really a SIMNow sentinel value. I don't think it belongs with common arch/io

File src/arch/x86/post.c:

https://review.coreboot.org/c/coreboot/+/61311/comment/7e02c43a_613fd4f2 
PS5, Line 10: 	if (CONFIG(CONSOLE_AMD_IO_PORT))
            : 		outl(AMD_IO_PORT_DATA_END, CONFIG_POST_IO_PORT);
Instead of modifying the common code, can we modify the simnow_tx_byte method to write the BEGIN byte, character byte, then END byte. Sure it will be slow, but simnow is already slow. This will keep the default ioport write working and hide all the simnow complexity.

File src/include/console/io_port.h:

PS5: 
Can we rename this to simnow.h?

File src/soc/amd/sabrina/bootblock.c:

https://review.coreboot.org/c/coreboot/+/61311/comment/d2f247af_b5bd4158 
PS5, Line 39: if (CONFIG(CONSOLE_AMD_IO_PORT))
            : 		outl(AMD_IO_PORT_DATA_BEGIN, CONFIG_POST_IO_PORT);
This should be done as part of the console_init