Revises microkernel semaphore sub-system to allow ISRs and fibers
to give a semaphore without having to define a command packet set.
The microkernel server now supports a 3rd command type on its
command stack, allowing a semaphore to be given in a similar manner
to the one used for the existing "give event" command type.
Change-Id: Ibd7fb1a77949792f72acd20a9ee304d6eabd62f7
Signed-off-by: Allan Stephens <allan.stephens@windriver.com>