app_loader Makefile: Add -d param to install call

This fixes the calls to make sure that the $(PREFIX)/lib and include
directories exist.

Signed-off-by: Frank Hunleth <fhunleth@troodon-software.com>
app_loader Makefile: clean up header file handling

Removed Makefile targets that would never be called and added the public
header files to the dependency list so that changes to them would
trigger .c file recompilation.

Signed-off-by: Frank Hunleth <fhunleth@troodon-software.com>
prussdrv: add prussdrv_exec_code function

This adds a helper function for loading PRU code from memory. This is
handy when building the PRU code into the application executable with
a header file generated by "pasm -c".

This is based on similar functions found in various am335x_pru_package
forks.

Signed-off-by: Frank Hunleth <fhunleth@troodon-software.com>
prussdrv: Remove unnecessary pthreads dependency

This removes the helper function for creating a pthread and the rest of
the infrastructure around it. Now the library can be linked in
environments that don't have pthreads. Also, the pthread helper code is
easily replicated in a user application and probably makes more sense
there anyway so that the user is more aware of the threading.

Signed-off-by: Frank Hunleth <fhunleth@troodon-software.com>
Merge remote-tracking branch 'fhunleth/makefile-fixes'
Merge remote-tracking branch 'fhunleth/prussdrv_exec_code'
Merge remote-tracking branch 'fhunleth/no_pthreads'

Removed prussdrv_start_irqthread from header because it is not
implemented any longer

Conflicts:
	pru_sw/app_loader/include/prussdrv.h