Fix #632, Infer OSAL_SYSTEM_BSPTYPE from CFE_SYSTEM_PSP_NAME

[jphickey]

Describe the contribution
Normally the CFE PSP uses/links with an OSAL BSP of the same name. This removes the need to explicitly specify OSAL_SYSTEM_BSPTYPE in the toolchain file, as it can be reliably inferred.

Fixes #632

This is also another alternative way to fix #629

Testing performed
Build with defaults (as in README, e.g. a simple make prep), as well as SIMULATION=native, and for i686-rtems4.11 platform. Confirm successful build.

Also "forced" a mismatch by hacking the i686-rtems4.11 toolchain to request bad combinations, and confirm that the build system warns of the mismatch now:

If OSAL_SYSTEM_BSPTYPE is set to pc-linux, the following warning happens in make prep

CMake Warning at cmake/arch_build.cmake:334 (message):
  Mismatched PSP/BSP: pc-rtems implies pc-rtems, but pc-linux is configured
Call Stack (most recent call first):
  CMakeLists.txt:119 (process_arch)

Likewise if the OSAL_SYSTEM_OSTYPE is set to posix, the follow is seen (from OSAL):

CMake Warning at /home/joe/code/cfecfs/github/osal/CMakeLists.txt:138 (message):
  Mismatched BSP/OS: pc-rtems implies rtems, but posix is configured

Finally removed settings of OSAL_SYSTEM_OSTYPE and OSAL_SYSTEM_BSPTYPE from the toolchain and confirmed that code correctly builds without issue, using the pc-rtems BSP and rtems OS layers, as expected for this toolchain.

Expected behavior changes

• Mismatches between PSP/BSP/OS are now detected and warned about during make prep
• Only the CFE_SYSTEM_PSPNAME is actually required to be specified for a CFE build now. Others can be omitted.

System(s) tested on
Ubuntu 18.04 LTS 64 bit, with i686-rtems4.11 cross target

Additional context
The related change to infer OSAL_SYSTEM_OSTYPE from OSAL_SYSTEM_BSPTYPE is in nasa/osal#432 and pull request nasa/osal#427. If it is desired to merge separately this can still be merged but it will have to continue setting OSAL_SYSTEM_OSTYPE.

Contributor Info - All information REQUIRED for consideration of pull request
Joseph Hickey, Vantage Systems, Inc.

[astrogeco]

CCB 20200422 - Merge together with osal side. APPROVED - FAST TRACK