x86: qemu: split qfw command interface and qfw core

This patch splits qfw command interface and qfw core function into two
files, and introduces a new Kconfig option (CONFIG_QFW) for qfw core.

Now when qfw command interface is enabled, it will automatically select
qfw core. This patch also makes the ACPI table generation select
CONFIG_QFW.

Signed-off-by: Miao Yan <yanmiaobest@gmail.com>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
diff --git a/drivers/misc/Makefile b/drivers/misc/Makefile
index 5969d34..4893086 100644
--- a/drivers/misc/Makefile
+++ b/drivers/misc/Makefile
@@ -43,3 +43,4 @@
 obj-$(CONFIG_RESET) += reset-uclass.o
 obj-$(CONFIG_FSL_DEVICE_DISABLE) += fsl_devdis.o
 obj-$(CONFIG_WINBOND_W83627) += winbond_w83627.o
+obj-$(CONFIG_QFW) += qemu_fw_cfg.o