boardid: Switch from Kconfig to weak functions

This patch switches the board_id and ram_code helper framework to use
weak functions rather than Kconfigs to determine whether the board
supplies these IDs. This cuts down on the amount of boilerplate Kconfigs
many boards have to set and also gives them more flexibility, such as
being able to determine at runtime whether a given ID is present.

Change-Id: I97d6d1103ebb2a2a7cf1ecfc45709c7e8c1a5cb0
Signed-off-by: Julius Werner <jwerner@chromium.org>
Reviewed-on: https://review.coreboot.org/22695
Reviewed-by: Aaron Durbin <adurbin@chromium.org>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

src/Kconfig

@@ -236,12 +236,6 @@ config UPDATE_IMAGE
 
 	  If unsure, select 'N'
 
-config RAM_CODE_SUPPORT
-	bool
-	help
-	  If enabled, coreboot discovers RAM configuration (value obtained by
-	  reading board straps) and stores it in coreboot table.
-
 config BOOTSPLASH_IMAGE
 	bool "Add a bootsplash image"
 	help
@@ -1207,13 +1201,6 @@ config DIMM_SPD_SIZE
 config SPD_READ_BY_WORD
 	bool
 
-config BOARD_ID_AUTO
-	bool
-	default n
-	help
-	  Mainboards that can read a board ID from the hardware straps
-	  (ie. GPIO) select this configuration option.
-
 config BOOTBLOCK_CUSTOM
 	# To be selected by arch, SoC or mainboard if it does not want use the normal
 	# src/lib/bootblock.c#main() C entry point.