s5j/serial: fix UART problem caused by executing ioctl()'s TCSETS

s5j/serial: fix UART problem caused by executing ioctl()'s TCSETS

This patch fixes UART commucation problem that occurs after executing
ioctl()'s TCSETS case. Because the TCSETS executes up_setup() which
disables all interrupts, UART commucation will be blocked after doing
ioctl()'s TCSETS case. In ioctl()'s TCSETS case, this patch replaces
up_setup() with up_configure(). The up_configure() function configures
baud, bits, parity and etc. without disabling all interrupts.

Change-Id: I43c624c13e37d883553ca0b0f498fb9a1663150d
Signed-off-by: Wonsang Ryou <wonsang.yoo@samsung.com>