alarm: display fast-wakeup status
alarm: display fast-wakeup status

Interesting when comparing ACLK and SMCLK: With fast wakeup disabled on
MSP430F5438A ACLK-based alarms incur a 3+-tick (~150us) delay, but SMCLK
ones appear as though fast wakeup was enabled.  Absent UCS errata this
is explained by active SMCLK preventing the system from entering LPM3 so
no long wakeup is required.

pabigot/bsp430,pabigot/bsp430,pabigot/bsp430,pabigot/bsp430