cmd: qfw: rename qemu_fw_cfg.[c|h] to qfw.[c|h]

Make file names consistent with CONFIG_QFW and CONFIG_CMD_QFW

Signed-off-by: Miao Yan <yanmiaobest@gmail.com>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
diff --git a/arch/x86/cpu/qemu/cpu.c b/arch/x86/cpu/qemu/cpu.c
index 4d2989a..b1a965e 100644
--- a/arch/x86/cpu/qemu/cpu.c
+++ b/arch/x86/cpu/qemu/cpu.c
@@ -8,7 +8,7 @@
 #include <cpu.h>
 #include <dm.h>
 #include <errno.h>
-#include <qemu_fw_cfg.h>
+#include <qfw.h>
 #include <asm/cpu.h>
 
 DECLARE_GLOBAL_DATA_PTR;