soc/intel/skylake: Use common UART device list driver

Remove platform-specific uart.c and switch to the common UART device
list driver. This eliminates 12 lines of duplicate code.

The Skylake uart.c simply defined uart_devices[] array. The common
driver now handles this using the PCI_DEVFN_UARTn macros defined in
pci_devs.h.

This commit:
- Adds PCI_DEVFN_UART* aliases pointing to PCH_DEVFN_UART* for naming
  consistency with common code
- Selects SOC_INTEL_COMMON_FEATURE and
  SOC_INTEL_COMMON_FEATURE_UART_DEVICES in Kconfig
- Removes uart.c and updates Makefile.mk

Change-Id: Id686de6bb4dd9ccf78644817881b2abfb5ae0352
Signed-off-by: Jeremy Compostella <jeremy.compostella@intel.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/91249
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Matt DeVillier <matt.devillier@gmail.com>

src/soc/intel/skylake/Kconfig

@@ -58,6 +58,8 @@ config SOC_INTEL_COMMON_SKYLAKE_BASE
 	select SOC_INTEL_COMMON_BLOCK_THERMAL_PCI_DEV
 	select SOC_INTEL_COMMON_BLOCK_UART
 	select SOC_INTEL_COMMON_BLOCK_XHCI_ELOG
+	select SOC_INTEL_COMMON_FEATURE
+	select SOC_INTEL_COMMON_FEATURE_UART_DEVICES
 	select SOC_INTEL_COMMON_FSP_RESET
 	select SOC_INTEL_COMMON_PCH_CLIENT
 	select SOC_INTEL_COMMON_NHLT

src/soc/intel/skylake/Makefile.mk

@@ -17,14 +17,12 @@ bootblock-y += p2sb.c
 bootblock-y += pmutil.c
 bootblock-y += spi.c
 bootblock-y += lpc.c
-bootblock-y += uart.c
 
 verstage-y += gpio.c
 verstage-y += gspi.c
 verstage-y += pmutil.c
 verstage-y += i2c.c
 verstage-y += spi.c
-verstage-y += uart.c
 
 romstage-y += gpio.c
 romstage-y += gspi.c
@@ -34,7 +32,6 @@ romstage-y += pcie_rp.c
 romstage-y += pmutil.c
 romstage-y += reset.c
 romstage-y += spi.c
-romstage-y += uart.c
 
 ramstage-$(CONFIG_HAVE_ACPI_TABLES) += acpi.c
 ramstage-y += chip.c
@@ -58,7 +55,6 @@ ramstage-y += reset.c
 ramstage-y += sd.c
 ramstage-y += spi.c
 ramstage-y += systemagent.c
-ramstage-y += uart.c
 ramstage-y += vr_config.c
 ramstage-y += xhci.c
 
@@ -67,13 +63,11 @@ smm-y += gpio.c
 smm-y += p2sb.c
 smm-y += pmutil.c
 smm-y += smihandler.c
-smm-y += uart.c
 smm-y += xhci.c
 
 postcar-y += gspi.c
 postcar-y += spi.c
 postcar-y += i2c.c
-postcar-y += uart.c
 
 ifeq ($(CONFIG_SKYLAKE_SOC_PCH_H),y)
 ifeq ($(CONFIG_MAINBOARD_SUPPORTS_SKYLAKE_CPU),y)

src/soc/intel/skylake/include/soc/pci_devs.h

@@ -187,4 +187,9 @@
 #define  PCH_DEV_GBE		_PCH_DEV(LPC, 6)
 #define  PCH_DEV_TRACEHUB	_PCH_DEV(LPC, 7)
 
+/* for common code */
+#define PCI_DEVFN_UART0		PCH_DEVFN_UART0
+#define PCI_DEVFN_UART1		PCH_DEVFN_UART1
+#define PCI_DEVFN_UART2		PCH_DEVFN_UART2
+
 #endif

src/soc/intel/skylake/uart.c

@@ -1,12 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0-only */
-
-#include <commonlib/helpers.h>
-#include <soc/pci_devs.h>
-
-const unsigned int uart_devices[] = {
-	PCH_DEVFN_UART0,
-	PCH_DEVFN_UART1,
-	PCH_DEVFN_UART2,
-};
-
-const int uart_devices_size = ARRAY_SIZE(uart_devices);