serial: 8250: Move ns16550a_goto_hispeed() to local header

Prepare for 8250_core.c file split; move shared inline function
to local header file.

Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2 files changed