The Acorn i2c driver (for RiscPC) triggers the "i2c adapter has no name"
warning in the I2C core driver, resulting in the RTC being inaccessible.
Fix this.

Fixes: 2236baa7 ("i2c: Sanity checks on adapter registration")
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Cc: stable@kernel.org