mtd: maps: vmu: add include to ensure maple mtd code builds

maple.h included in vmu-flash.c references struct device and struct device_driver, so we should explicitly include linux/device.h to ensure the code builds without error.

Include header file required for build.

---
 drivers/mtd/maps/vmu-flash.c | 1 +
 1 file changed, 1 insertion(+)

index 75e06d249ce9..e2a574a4b438 100644
@@ -9,6 +9,7 @@
 #include <linux/slab.h>
 #include <linux/sched.h>
 #include <linux/delay.h>
+#include <linux/device.h>
 #include <linux/maple.h>
 #include <linux/mtd/mtd.h>
 #include <linux/mtd/map.h>

2.43.0