Renamed mpu testsuite directory for future changes.

mpu_testsuite/mpu_apps/Readme.txt

mpu_testsuite/mpu_apps/build.sh

mpu_testsuite/mpu_apps/cleanup.sh

mpu_testsuite/mpu_apps/mpu_testsuite.cpp

mpu_testsuite/mpu_apps/test1/Makefile

mpu_testsuite/mpu_apps/test1/crt0.s

mpu_testsuite/mpu_apps/test1/main.c

mpu_testsuite/mpu_apps/test1/miosix.ld

mpu_testsuite/mpu_apps/test2/Makefile

mpu_testsuite/mpu_apps/test2/crt0.s

mpu_testsuite/mpu_apps/test2/includes.h

mpu_testsuite/mpu_apps/test2/main.c

mpu_testsuite/mpu_apps/test2/miosix.ld