altos: Oops. Serial 1 stdin was busted by typo

A typo in the symbol used to enable stdin wakeups from serial1 caused
the input to pend until some other wakeup occurred.

This also makes the serial1 hw flow control pin selects in config 2
work right, although those aren't used by any current product

Signed-off-by: Keith Packard <keithp@keithp.com>