This adds support for EARLY_PRINTF via the CFE console; the aim is to
provide a fix for the otherwise cyclic dependency between PMU detection
and console printf/DELAY:
- We need to parse the bhnd(4) core table to determine the address (and type) of the PMU/PLL registers and calculate the CPU clock frequency.
- The core table parsing code will emit a printf() if a parse error is hit.
- Calling printf() without EARLY_PRINTF requires a working DELAY, which means we need the PMU.
Errors in core table parsing shouldn't happen, but lack of EARLY_PRINTF
makes debugging more difficult.
PMU detection hasn't been dropped in yet; the end-goal is to use the new
PMU code (D7492) to query the actual clockspeed as configured by the boot
loader (and in NVRAM), rather than assuming a fixed clock speed for a given
chip identifier.