The RTEMS Software Engineering Guide specifies that the SPDX license
annotation shouldbe the first line of the file and not part of the
copyright/license comment block.
Replace the BSP_CONSOLE_MINOR BSP option for the Xilinx Zynq BSPs with the new
BSP option ZYNQ_UART_KERNEL_IO_BASE_ADDR. Move the kernel I/O support to a
shared file.
Make the initialization and polled functions independent of the Termios
context. This helps to implement the kernel I/O support without a dependency
on the Termios framework.
