From the User Manual, there are 6 steps in the initialization process. One of
which turns to PCLK on for the UART.
The baud rate calculation doesn't look right. Even if the registers are
loaded, all you're going to get is a baud rate 1/16 of PCLK and that's
usually pretty fast. Then there is the fraction divider...
Take a look at the relevant chapter in the User Manual and see if it helps.