lib/coreboot_table: Simplify API to set up lb_serial

Instead of having callbacks into serial console code to set up the
coreboot table have the coreboot table code call IP specific code to get
serial information. This makes it easier to reuse the information as the
return value can be used in a different context (e.g. when filling in a
FDT).

This also removes boilerplate code to set up lb_console entries by
setting entry based on the type in struct lb_uart.

Change-Id: I6c08a88fb5fc035eb28d0becf19471c709c8043d
Signed-off-by: Arthur Heymans <arthur@aheymans.xyz>
---
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/boot/coreboot_tables.h
M src/lib/coreboot_table.c
M src/mainboard/emulation/qemu-power8/uart.c
M src/soc/mediatek/common/uart.c
M src/soc/nvidia/tegra124/uart.c
M src/soc/nvidia/tegra210/uart.c
M src/soc/qualcomm/common/qupv3_uart.c
M src/soc/qualcomm/common/uart_bitbang.c
M src/soc/qualcomm/ipq40xx/uart.c
M src/soc/qualcomm/ipq806x/uart.c
M src/soc/qualcomm/qcs405/uart.c
M src/soc/samsung/exynos5250/uart.c
M src/soc/samsung/exynos5420/uart.c
M src/soc/ti/am335x/uart.c
M tests/lib/coreboot_table-test.c
19 files changed, 142 insertions(+), 170 deletions(-)