altoslib: Keep config data accel cal in antenna up form.

Instead of letting the accel cal data live in whatever form it was
fetched in, keep it in antenna up form and provide it in whatever
orientation is necessary.

This fixes bugs in changing pad configuration where the accel cal values
from the old orientation would get used in the new orientation and
wreck them.

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