serial: lpc32xx: send CR before LF

For LPC32XX high-speed UART it is required to send a carriage return
symbol along with line feed. The problem was introduced in e503f90a
commit.

Signed-off-by: Vladimir Zapolskiy <vz@mleia.com>
Cc: Marek Vasut <marex@denx.de>
Acked-by: Marek Vasut <marex@denx.de>