fix; Replace SleepTask::bootBehavior accesses with NVRAM Accesses

[ntlhui]

SleepTask currently has a static variable SleepTask::bootBehavior that is used to cache the boot behavior value. This is backed by NVRAM accesses. However, these might not be always synchronized.

Please consolidate all accesses to the logical boot behavior value to NVRAM accesses.

[ntlhui]

See

smartfin-fw3/src/sleepTask.cpp

Line 11 in fcb09e1

SleepTask::BOOT_BEHAVIOR_e SleepTask::bootBehavior;

,

smartfin-fw3/src/sleepTask.hpp

Line 50 in fcb09e1

static BOOT_BEHAVIOR_e bootBehavior;