* arch/arm/src/tiva/common/tiva_serial.c:
(up_ioctl): PR #8406 (commit 1edec0aaa1) added support for
configuring the serial port's CTS/RTS flow control at runtime using
termios when built with CONFIG_SERIAL_TERMIOS and either or both of
CONFIG_SERIAL_OFLOWCONTROL and CONFIG_SERIAL_IFLOWCONTROL. However,
a runtime sanity check left over from before prevented this from
working: When processing ioctl TCSETS, we would return -EINVAL if
one or both of CCTS_OFLOW and CRTS_IFLOW were requested, which was
not deserved if the requested features were in fact supported.
Fixing the sanity check so it depends on features actually
configured.
5d2e1d40dc