char/tpm: Convert struct i2c_msg initialization to C99 format

Convert the struct i2c_msg initialization to C99 format. This makes
maintaining and editing the code simpler. Also helps once other fields
like transferred are added in future.

Thanks to Julia Lawall for automating the conversion.

Signed-off-by: Shubhrajyoti D <shubhrajyoti@ti.com>
Acked-by: Peter Huewe <peter.huewe@infineon.com>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Kent Yoder <key@linux.vnet.ibm.com>