[RAPIDIO] Change RapidIO doorbell source and target ID field to 16-bit

#define DOORBELL_DSR_TE		0x00000080

#define DOORBELL_DSR_QFI	0x00000010

#define DOORBELL_DSR_DIQI	0x00000001

#define DOORBELL_TID_OFFSET	0x03

#define DOORBELL_SID_OFFSET	0x05

#define DOORBELL_TID_OFFSET	0x02

#define DOORBELL_SID_OFFSET	0x04

#define DOORBELL_INFO_OFFSET	0x06

#define DOORBELL_MESSAGE_SIZE	0x08

#define DBELL_SID(x)		(*(u8 *)(x + DOORBELL_SID_OFFSET))

#define DBELL_TID(x)		(*(u8 *)(x + DOORBELL_TID_OFFSET))

#define DBELL_SID(x)		(*(u16 *)(x + DOORBELL_SID_OFFSET))

#define DBELL_TID(x)		(*(u16 *)(x + DOORBELL_TID_OFFSET))

#define DBELL_INF(x)		(*(u16 *)(x + DOORBELL_INFO_OFFSET))

struct rio_atmu_regs {