x86: edison: Bring minimal ACPI support to the board

This board is based on Intel Tangier SoC (Intel Merrifield platform)
and may utilize ACPI powerfulness.

Bring minimum support by appending initial DSDT table for it.

Note, the addresses for generated tables are carefully chosen to avoid
any conflicts with existing shadowed BIOS data. The user have somewhat
like ~31 kB available for compiled ACPI tables that ought to be enough.

Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>

board/intel/edison/.gitignore

@@ -0,0 +1,3 @@
+dsdt.aml
+dsdt.asl.tmp
+dsdt.c

board/intel/edison/Kconfig

@@ -15,6 +15,12 @@ config SYS_CONFIG_NAME
 config SYS_TEXT_BASE
 	default 0x01101000
 
+config ROM_TABLE_ADDR
+	default 0x0e4500
+
+config ROM_TABLE_SIZE
+	default 0x007b00
+
 config BOARD_SPECIFIC_OPTIONS # dummy
 	def_bool y
 	select X86_LOAD_FROM_32_BIT

board/intel/edison/Makefile

@@ -5,3 +5,4 @@
 #
 
 obj-y	+= start.o edison.o
+obj-$(CONFIG_GENERATE_ACPI_TABLE) += dsdt.o

board/intel/edison/dsdt.asl

@@ -0,0 +1,13 @@
+/*
+ * Copyright (c) 2017 Intel Corporation
+ *
+ * Partially based on dsdt.asl for other x86 boards
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+DefinitionBlock("dsdt.aml", "DSDT", 2, "U-BOOT", "U-BOOTBL", 0x00010000)
+{
+	/* platform specific */
+	#include <asm/arch/acpi/platform.asl>
+}

include/configs/edison.h

@@ -9,6 +9,9 @@
 
 #include <asm/ibmpc.h>
 
+/* ACPI */
+#define CONFIG_LAST_STAGE_INIT
+
 /* Boot */
 #define CONFIG_BOOTCOMMAND "run bootcmd"