sparc: Merge asm-sparc{,64}/termios.h

Bring the commit e55c57e0
("[SPARC64]: Report any user access faults in termios accessors")
over to sparc when unifying the two files.
The diff was manually inspected to contain no
other relevant changes.

This unification therefore changes functionality of sparc.

Signed-off-by: Sam Ravnborg <sam@ravnborg.org>