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/cmd/qfw.c b/cmd/qfw.c
index 37f1aa6..c6730bf 100644
--- a/cmd/qfw.c
+++ b/cmd/qfw.c
@@ -7,7 +7,7 @@
 #include <common.h>
 #include <command.h>
 #include <errno.h>
-#include <qemu_fw_cfg.h>
+#include <qfw.h>
 
 /*
  * This function prepares kernel for zboot. It loads kernel data