[U-Boot] [PATCH 15/15] sandbox: Restore blocking I/O on exit

[sjg at google.com]

At present sandbox sets non-blocking I/O as soon as any input is read
from the terminal. However it does not restore the previous state on
exit. Fix this and drop the old os_read_no_block() function.

This means that we always enable blocking I/O in sandbox (if input is a
terminal) whereas previously it would only happen on the first call to
tstc() or getc(). However, the difference is likely not important.

Signed-off-by: Simon Glass <sjg at chromium.org>
---

 arch/sandbox/cpu/os.c    | 23 +++++++++++++++--------
 drivers/serial/sandbox.c |  2 +-
 include/os.h             | 10 ----------
 3 files changed, 16 insertions(+), 19 deletions(-)

Applied to u-boot-dm