vsprintf: Fix build warnings

Lots of "unused variable" and "definition differs" warnings cleaned up.

Signed-off-by: Sean Cross <xobs@kosagi.com>
os: hal: Bring RTC support from upstream

For some reason, the git repo doesn't seem to be updating.  Manually
pull in upstream RTC support for STM32.

Signed-off-by: Sean Cross <xobs@kosagi.com>
senoko: Update halconf to enable RTC

Since the RTC is ostensibly supported now, enable it.

Signed-off-by: Sean Cross <xobs@kosagi.com>
chg: Support pausing charge thread

Sometimes we want to stop the main system from updating the charging thread,
such as when we're manipulating the gas gauge.  Add functions to allow this.

Signed-off-by: Sean Cross <xobs@kosagi.com>
cmd-chg: Refactor, document, support pausing chg thd

Refactor the chg command to bring it up to par with the gg command. As
part of this refactor, add commands to pause the charge thread.

Signed-off-by: Sean Cross <xobs@kosagi.com>
localtime: Add our own version of mktime

This is ported from BSD, and has had all the tzfile stuff ripped
out.  This allows it to fit in our small profile, but admittedly
means we don't get things like leap seconds or daylight saving.

Signed-off-by: Sean Cross <xobs@kosagi.com>
cmd-date: Add command to get/set the date

It is very rudimentary, but appears to prove functionality of the RTC.

Signed-off-by: Sean Cross <xobs@kosagi.com>
senoko-shell: Add date command

Signed-off-by: Sean Cross <xobs@kosagi.com>