nimble/phy: Change TX scheduling in RX-TX transition
nimble/phy: Change TX scheduling in RX-TX transition

We fail to reply AUX_ADV_IND with a AUX_CONNECT_REQ if auxiliary packet
was received on LE Coded S8 phy. This is because time required to
process this packet is rought the same as when we need to enable radio
before transmission so we simply miss the slot and set the timer0 to
fire in the past.

The solution is to setup timer0 before processing the packet so radio
can be enabled on time and in case we don't need to tx anything we'll
just disable the timer and nothing will be transmitted.

X-Original-Commit: bb48d9e20e25f952ec085cca34f75967b54fca84

apache/mynewt-nimble,apache/mynewt-nimble,apache/mynewt-nimble,apache/mynewt-nimble,apache/mynewt-nimble