arm: lpc32xx: switch serial console to driver model

On NXP LPC32xx platform for non-SPL builds the change adds
standard (NS16550) and high-speed UARTs to driver model.
Due to specific of DM NS16550 device description UART clock can not be
got in runtime and by default it is set to 13MHz, if board PERIPH_CLK
is different, this should be specified in board configuration file.

For SPL builds HSUARTs are disabled and non-DM NS16550 driver is
compiled, if needed.

The change also updates default configs of devkit3250 and work_92105
boards to reflect updates in platform files.

Signed-off-by: Vladimir Zapolskiy <vz@mleia.com>
Reviewed-by: Simon Glass <sjg@chromium.org>