rtc: Add SPI alias for pcf2123 driver

raspberrypi inclusion
category: feature
bugzilla: 50432

--------------------------------

Without this alias, Device Tree won't cause the driver
to be loaded.

See: https://github.com/raspberrypi/linux/pull/1510Signed-off-by: NFang Yafen <yafen@iscas.ac.cn>
Signed-off-by: NZheng Zengkai <zhengzengkai@huawei.com>

drivers/rtc/rtc-pcf2123.c

@@ -465,3 +465,4 @@ module_spi_driver(pcf2123_driver);
 MODULE_AUTHOR("Chris Verges <chrisv@cyberswitching.com>");
 MODULE_DESCRIPTION("NXP PCF2123 RTC driver");
 MODULE_LICENSE("GPL");
+MODULE_ALIAS("spi:rtc-pcf2123");