Revert "serial: omap: fix software flow control"

commit a4f743851f74fc3e0cc40c13082e65c24139f481 upstream.

This reverts commit 957ee7270d632245b43f6feb0e70d9a5e9ea6cf6
(serial: omap: fix software flow control).

As Russell has pointed out, that commit isn't fixing
Software Flow Control at all, and it actually makes
it even more broken.

It was agreed to revert this commit and use Russell's
latest UART patches instead.

Signed-off-by: Felipe Balbi <balbi@ti.com>
Cc: Russell King <linux@arm.linux.org.uk>
Acked-by: Tony Lindgren <tony@atomide.com>
Cc: Andreas Bießmann <andreas.devel@googlemail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>