mfd: qnap-mcu: Include linux/types.h in qnap-mcu.h shared header

Relying on other components to include those basic types is unreliable
and may cause compile errors like:

../include/linux/mfd/qnap-mcu.h:13:9: error: unknown type name ‘u32’
13 | u32 baud_rate;
| ^~~
../include/linux/mfd/qnap-mcu.h:17:9: error: unknown type name ‘bool’
17 | bool usb_led;
| ^~~~

So make sure, the types used in the header are available.

Signed-off-by: Heiko Stuebner <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Lee Jones <[e-mail]>

include/linux/mfd/qnap-mcu.h

···
 #ifndef _LINUX_QNAP_MCU_H_
 #define _LINUX_QNAP_MCU_H_
 
+#include <linux/types.h>
+
 struct qnap_mcu;
 
 struct qnap_mcu_variant {