USB: serial: kobil_sct: restore initial terminal settings

Commit 6a6c8b36 ("usb, kobil: Sort out some bogus tty handling")
intended to fix and clean up the device-specific initial terminal
settings but instead confused the termios input and local control flags
and re-enabled ICRNL and IXON.

Drop the bogus masking of l-flags from the default i-flags (which has no
effect) and restore the original device-specific i-flags.

Fixes: 6a6c8b36 ("usb, kobil: Sort out some bogus tty handling")
Signed-off-by: Johan Hovold <johan@kernel.org>