A80 UART0 pinsets
Only need to SRTA if the device address is changing. Add AC100 device address.
Add support for 2- and 4- byte transfers
remove debug printf
Add driver for X-Powers AC100 integrated audio codec and RTC subsystem.
Only RTC functionality implemented for now.
add AC100 CODEC/RTC driver
only access A20 regs if running on A20