Revert "i2c: Try 12.8 MHz"

This reverts commit d080524a92739b7d64018688e7d53892fe44fd2c.
Revert "I2C: Try 14.4 MHz"

This reverts commit 3121da39a7719854baeb90632764a93fcf769e03.
i2c: Drop missing things to 19.2 MHz

Signed-off-by: Chet Kener <Cl3Kener@gmail.com>