SYS_ARCH_UNPROTECT macro

SYS_ARCH_UNPROTECT Perform a "fast" set of the protection level to "lev". This could be implemented by setting the interrupt level to "lev" within the MACRO or by using a semaphore or mutex. This macro will default to calling the sys_arch_unprotect() function which should be implemented in sys_arch.c. If a particular port needs a different implementation, then this macro may be defined in sys_arch.h