Using UART_* to name defines is a bit problematic. When trying to do
unrelated cleanup which also involved tweaking header inclusion logic,
caused UART_CSR from serial_reg.h to leak into msm's namespace which is
also among msm defines. Thus, rename all UART_* ones to MSM_UART_* to
avoid eliminate possibility of collisions.
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@xxxxxxxxxxxxxxx>