x86: qemu: Move qfw command over to cmd and add Kconfig entry

- Move the command portion of arch/x86/cpu/qemu/fw_cfg.c into
  cmd/qemu_fw_cfg.c
- Move arch/x86/include/asm/fw_cfg.h to include/qemu_fw_cfg.h
- Rename ACPI table portion to arch/x86/cpu/qemu/acpi_table.c

Signed-off-by: Tom Rini <trini@konsulko.com>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
diff --git a/arch/x86/lib/acpi_table.c b/arch/x86/lib/acpi_table.c
index 989cf7d..be7b824 100644
--- a/arch/x86/lib/acpi_table.c
+++ b/arch/x86/lib/acpi_table.c
@@ -303,7 +303,7 @@
 
 /*
  * QEMU's version of write_acpi_tables is defined in
- * arch/x86/cpu/qemu/fw_cfg.c
+ * arch/x86/cpu/qemu/acpi_table.c
  */
 u32 write_acpi_tables(u32 start)
 {