coreboot_tables: Extend serial port description

Extend the serial port description to include the input clock frequency
and a payload specific value.

Without the input frequency it is impossible for the payload to compute
the baud-rate divisor without making an assumption about the frequency.
This breaks down when the UART is able to support multiple input clock
frequencies.

Add the UART_PCI_ADDR Kconfig value to specify the unique PCI device
being used as the console UART.  Specify this value as zero when the
UART is not on the PCI bus.  Otherwise specify the device using bus,
device and function along with setting the valid bit.

Currently the only payload to consume these new fields is the EDK-II
CorebootPayloadPkg.

Testing on Galileo:
*  Edit the src/mainboard/intel/galileo/Makefile.inc file:
   *  Add "select ADD_FSP_PDAT_FILE"
   *  Add "select ADD_FSP_RAW_BIN"
   *  Add "select ADD_RMU_FILE"
*  Place the FSP.bin file in the location specified by CONFIG_FSP_FILE
*  Place the pdat.bin files in the location specified by
   CONFIG_FSP_PDAT_FILE
*  Place the rmu.bin file in the location specified by CONFIG_RMU_FILE
*  Build EDK2 CorebootPayloadPkg/CorebootPayloadPkgIa32.dsc to generate
   UEFIPAYLOAD.fd
*  Testing is successful when CorebootPayloadPkg is able to properly
   initialize the serial port without using built-in values.

Change-Id: Id4b4455bbf9583f0d66c315d38c493a81fd852a8
Signed-off-by: Lee Leahy <leroy.p.leahy@intel.com>
Reviewed-on: https://review.coreboot.org/14609
Tested-by: build bot (Jenkins)
Reviewed-by: Martin Roth <martinroth@google.com>
diff --git a/src/drivers/uart/uart8250mem.c b/src/drivers/uart/uart8250mem.c
index 278ddb8..2f2bd2d 100644
--- a/src/drivers/uart/uart8250mem.c
+++ b/src/drivers/uart/uart8250mem.c
@@ -156,6 +156,11 @@
 		serial.regwidth = sizeof(uint32_t);
 	else
 		serial.regwidth = sizeof(uint8_t);
+	if (IS_ENABLED(CONFIG_UART_USE_REFCLK_AS_INPUT_CLOCK))
+		serial.input_hertz = uart_platform_refclk();
+	else
+		serial.input_hertz = 0;
+	serial.uart_pci_addr = CONFIG_UART_PCI_ADDR;
 	lb_add_serial(&serial, data);
 
 	lb_add_console(LB_TAG_CONSOLE_SERIAL8250MEM, data);