[U-Boot] unused-const-variable warnings in FSL I2C driver

Hi all,

When compiling latest u-boot with gcc 6.3 for a T1024RDB system, I get a 'unused-const-variable' warning in the FSL I2C driver. Affected variable is fsl_i2c_speed_map.

I guess this warning can be fixed with the patch applied, but I'm not sure. What do you think?

Best regards, Thomas