dm: i2c-uclass-compat: fix missed argument

This patch fixes build error for CONFIG_DM_I2C_COMPAT.
In i2c_get_chip_for_busnum() call, one of argument was missed,
which was offset_len. Now it is set to 'alen' as previous.

Signed-off-by: Przemyslaw Marczak <p.marczak@samsung.com>
Acked-by: Simon Glass <sjg@chromium.org>
1 file changed