Update Ticker wrapper to handle early interrupts

[c1728p9]

Description

Update the LowPowerTickerWrapper class to handle rather than ignore early low power ticker interrupts. This ensures that devices don't get stuck in sleep due to a ignored early low power ticker interrupt.

Pull request type

[x] Fix
[ ] Refactor
[ ] Target update
[ ] Functionality change
[ ] Docs update
[ ] Test update
[ ] Breaking change

[c1728p9]

This PR will cause more frequent low power ticker rescheduling and removes code which prevents violating this part of the HAL specification:

mbed-os/hal/us_ticker_api.h

Lines 70 to 71 in f8e1116

	* * The ticker interrupt fires only when the ticker times increments to or past the value set by ticker_set_interrupt.
	* Verified by ::ticker_interrupt_test and ::ticker_past_test

The benefit this brings is greatly increased stability since early low power ticker interrupts won't cause a lockup, as is the case in #8906.

[cmonr]

LGTM

[cmonr]

Change looks good to me, but @c1728p9 I'm wondering if this also needs input from Partners (ping @ashok-rao @MarceloSalazar @screamerbg) or @ARMmbed/mbed-os-hal

[cmonr]

Marking for 11.1 since this feels like it's a fix, but could also be seen as a breaking change, pushing it out to 12.0-rc1

[klaas019]

@cmonr
This fix along with #8777 appears to fix #8906. Would be nice to get this in 11.1 instead of 12.0-rc1 as #8777 is scheduled for 11.1, since lowpower ticker/timeout is broken as of 5.10.3 for st devices.

[cmonr]

@klaas019 Thanks for the context. Will keep at 11.1 for now.

[cmonr]

CI started

[mbed-ci]

Test run: SUCCESS

Summary: 4 of 4 test jobs passed
Build number : 1
Build artifacts
Build logs