i2c: davinci: Preserve return value of devm_clk_get

The i2c driver can run into driver dependency issues if its loaded
before a clock driver it depends on. Therefore, EPROBE_DEFER may be
returned by devm_clk_get and should be returned in probe to allow the
kernel to reprobe the driver at a later time. This patch allows the error
value returned by devm_clk_get to be passed through and not overwritten.

Signed-off-by: Franklin S Cooper Jr <fcooper@ti.com>
Reviewed-by: Grygorii Strashko <grygorii.strashko@ti.com>
Acked-by: Sekhar Nori <nsekhar@ti.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>