Specify layout of msmt_regs

[steven-bellock]

Given

/* Number of initial measurement registers */
uint_8 initial_measurements;
/* Number of runtime measurement registers */
uint_8 runtime_measurements;
/* Array of all measurement register descriptors */
MeasurementRegisterDescriptor[MAX_MEASUREMENT_REGISTERS] msmt_regs;

specify the layout of msmt_regs. In particular is the size of the array always MAX_MEASUREMENT_REGISTERS or does the size depend on the values of initial_measurements and runtime_measurements.