Adds a simple, tracepoint inspired hook definiton framework to centralize
all calls to rmnet support modules. Modules can set and unset these hooks
freely, and modules may call one another's hooks without being forced to
link against any module other than the core rmnet module.
Change-Id: I949f7a17c95003e0c79262c6611b0602c7189e0c
Signed-off-by: Sean Tranchetti <quic_stranche@quicinc.com>
