mb/purism/librem_cnl: Adjust in preparation for new variants

- Move the SoC select to board config (vs baseboard config)
- Qualify the VGA PCI ID and CBFS size values based on board selection
- Move devicetree to variant dir and add Kconfig entry
- Use a separate board_info.txt for the baseboard and each variant

Change-Id: I4764f2c1243ea49bd08e0735865cc3cb7a66441f
Signed-off-by: Matt DeVillier <matt.devillier@puri.sm>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/47051
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Angel Pons <th3fanbus@gmail.com>
Reviewed-by: Michael Niewöhner <foss@mniewoehner.de>

src/mainboard/purism/librem_cnl/Kconfig

@@ -9,7 +9,6 @@ config BOARD_PURISM_BASEBOARD_LIBREM_CNL
 	select NO_UART_ON_SUPERIO
 	select SOC_INTEL_COMMON_BLOCK_HDA
 	select SOC_INTEL_COMMON_BLOCK_HDA_VERB
-	select SOC_INTEL_WHISKEYLAKE
 	select SPD_READ_BY_WORD
 	select USE_LEGACY_8254_TIMER
 
@@ -31,9 +30,13 @@ config VARIANT_DIR
 	string
 	default "librem_mini" if BOARD_PURISM_LIBREM_MINI
 
+config DEVICETREE
+	string
+	default "variants/$(CONFIG_VARIANT_DIR)/devicetree.cb"
+
 config CBFS_SIZE
 	hex
-	default 0x800000
+	default 0x800000 if BOARD_PURISM_LIBREM_MINI
 
 config MAX_CPUS
 	int
@@ -49,7 +52,7 @@ config DIMM_SPD_SIZE
 
 config VGA_BIOS_ID
 	string
-	default "8086,3ea0"
+	default "8086,3ea0" if BOARD_PURISM_LIBREM_MINI
 
 config PXE_ROM_ID
 	string

src/mainboard/purism/librem_cnl/Kconfig.name

@@ -1,3 +1,4 @@
 config BOARD_PURISM_LIBREM_MINI
 	bool "Librem Mini"
 	select BOARD_PURISM_BASEBOARD_LIBREM_CNL
+	select SOC_INTEL_WHISKEYLAKE

src/mainboard/purism/librem_cnl/board_info.txt

@@ -1,6 +1,6 @@
 Vendor name: Purism
-Board name: librem_cnl
-Category: desktop
+Board name: Librem Cannonlake baseboard
+Category: misc
 Release year: 2020
 ROM package: SOIC-8
 ROM protocol: SPI

src/mainboard/purism/librem_cnl/variants/librem_mini/board_info.txt

@@ -0,0 +1,8 @@
+Vendor name: Purism
+Board name: Librem Mini
+Category: desktop
+Release year: 2020
+ROM package: SOIC-8
+ROM protocol: SPI
+ROM socketed: n
+Flashrom support: y