Add uart configuration for UART driver, add frdm_ke17z512_uart.overlay
and update testcase.yml to support UART testing.
There are LPUART and UART IPs in frdm_ke17z512 platforms, so add
additional shell tests as UART, the shell instructions can be entered
on the UART console window.
Signed-off-by: Anke Xiao <anke.xiao@nxp.com>