6621E/F新增读取flash uid接口函数

部分客户反馈6261E和6621F没有获取flash uid的接口，这个接口，我们自己可以封装一下。操作如下：

#define SF_RW_PARAM_CMD_ADDR_40BITS_DECLARE(name, cmd, addr, data, len) \

sfb_rw_params_t name = {{{((cmd)<<24)|(addr), 0}}, 40, (data), (len)}

#define SPI_CMD_RDUID       0x4Bu /* Read UID */

void sf_read_uid_ex(HS_SF_Type *sf, uint32_t cs, void *data, uint32_t length)

{   

    SF_RW_PARAM_CMD_ADDR_40BITS_DECLARE(param, SPI_CMD_RDUID, 0, data, length);

    sfb_read_nodma(sf, cs, &param);

}