soc/apollolake: Add early serial driver for BOOTBLOCK_CONSOLE

Early UART driver is for bootblock and romstage. It is supposed to be used
when BOOTBLOCK_CONSOLE is enabled. This also adds few configuration bits
in bootblock requiered for serial to be set up.

Change-Id: I15520d566f107797e68d618885d4379e73d0fa45
Signed-off-by: Andrey Petrov <andrey.petrov@intel.com>
Reviewed-on: https://review.coreboot.org/13677
Tested-by: build bot (Jenkins)
Reviewed-by: Aaron Durbin <adurbin@chromium.org>

src/soc/intel/apollolake/Kconfig

@@ -32,6 +32,13 @@ config CPU_SPECIFIC_OPTIONS
 	select RELOCATABLE_RAMSTAGE	# Build fails if this is not selected
 	select SOC_INTEL_COMMON
 	select UDELAY_TSC
+	select CONSOLE_SERIAL
+	select BOOTBLOCK_CONSOLE
+	select TSC_CONSTANT_RATE
+	select UDELAY_TSC
+	select TSC_CONSTANT_RATE
+	select NO_UART_ON_SUPERIO
+	select DRIVERS_UART_8250MEM_32
 
 config MMCONF_BASE_ADDRESS
 	hex "PCI MMIO Base Address"
@@ -63,4 +70,9 @@ config CPU_ADDR_BITS
 	int
 	default 36
 
+config CONSOLE_UART_BASE_ADDRESS
+	depends on CONSOLE_SERIAL
+	hex "MMIO base address for UART"
+	default 0xde000000
+
 endif