nimble/ll: Fix scheduling new connection in slave role
nimble/ll: Fix scheduling new connection in slave role

If we do ext adv with secondary on coded phy, we use coded s2 for rx.
If initiator sends AUX_CONNECT_REQ with s8, we'll calculate packet
length incorrectly and schedule connection event too early by ~2 msecs
which is the different between tx time of AUX_CONNECT_REQ on s8 and s2.

With this fix we'll use actual phy mode of the received packet so we
can schedule connection event properly.

X-Original-Commit: 99f81e5d2ca59989852fd64f9c1a0abdd1c8428f

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