acpi: Kconfig symbol CONFIG_QFW_ACPI

We have two implementations of write_acpi_tables(). One for writing ACPI
tables based on ACPI_WRITER() entries another based on copying tables from
QEMU.

Create a symbol CONFIG_QFW_ACPI that signifies copying ACPI tables from
QEMU and use it consistently.

Signed-off-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>
Reviewed-by: Simon Glass <sjg@chromium.org>

drivers/misc/Kconfig

@@ -540,6 +540,13 @@ config QFW
 	  Hidden option to enable QEMU fw_cfg interface and uclass. This will
 	  be selected by either CONFIG_CMD_QFW or CONFIG_GENERATE_ACPI_TABLE.
 
+config QFW_ACPI
+	bool
+	default y
+	depends on QFW && GENERATE_ACPI_TABLE && !SANDBOX
+	help
+	  Hidden option to read ACPI tables from QEMU.
+
 config QFW_PIO
 	bool
 	depends on QFW

drivers/misc/qfw.c

@@ -21,7 +21,7 @@
 #include <tables_csum.h>
 #include <asm/acpi_table.h>
 
-#if defined(CONFIG_GENERATE_ACPI_TABLE) && !defined(CONFIG_SANDBOX)
+#ifdef QFW_ACPI
 /*
  * This function allocates memory for ACPI tables
  *
@@ -259,7 +259,7 @@ ulong acpi_get_rsdp_addr(void)
 	file = qfw_find_file(dev, "etc/acpi/rsdp");
 	return file->addr;
 }
-#endif
+#endif /* QFW_ACPI */
 
 static void qfw_read_entry_io(struct qfw_dev *qdev, u16 entry, u32 size,
 			      void *address)