Change in coreboot[master]: Add console deinit API, use in SMM handler

[Deomid "rojer" Ryabkov (Code Review)]

Attention is currently required from: Deomid "rojer" Ryabkov.
Hello build bot (Jenkins),

I'd like you to reexamine a change. Please visit

https://review.coreboot.org/c/coreboot/+/56386

to look at the new patch set (#6).

Change subject: Add console deinit API, use in SMM handler
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Add console deinit API, use in SMM handler

SMM handler should return shared hardware to the state it was at the
time of the SMI call.
When CONFIG_DEBUG_SMI is enabled SMM handler performs console
hardware initialization that may interfere with OS.

Specifically, this has been observed with SMM handler output to UART:
uart8250_init disables interrupts because it uses polling but the Linux
kernel uses interrupts. As a result, SMI call leaves interrupts disabled
and causes OS console I/O issues.

For 8250, we save all the registers we touch in init and restore them in deinit.
Other deinit functions are provided as stubs only but should probably be
looked into as well.

Signed-off-by: Deomid "rojer" Ryabkov 
Change-Id: Ia5e51f385f83cb998c244ca1d1ffc10339d3a714
---
M src/console/console.c
M src/console/init.c
M src/cpu/x86/smm/smm_module_handler.c
M src/drivers/uart/pl011.c
M src/drivers/uart/sifive.c
M src/drivers/uart/uart8250io.c
M src/drivers/uart/uart8250mem.c
M src/include/console/cbmem_console.h
M src/include/console/console.h
M src/include/console/flash.h
M src/include/console/ne2k.h
M src/include/console/qemu_debugcon.h
M src/include/console/spi.h
M src/include/console/spkmodem.h
M src/include/console/streams.h
M src/include/console/system76_ec.h
M src/include/console/uart.h
M src/include/console/usb.h
18 files changed, 126 insertions(+), 2 deletions(-)

git pull ssh://review.coreboot.org:29418/coreboot refs/changes/86/56386/6