Add INVARIANTS to ARM64 DMAP_TO/TO_DMAP macros to catch out of range calls

KASSERTs will inform us when there was out of range PA or VA used
in DMAP_TO_PHYS() and PHYS_TO_DMAP().
Fix failure during initialization due to out of range DMAP allocations

Let the kernel direct map be as large as possible, which means
64GB 0x0 - 0xfffffffff. This fixes all issues related to calls
to DMAP for physical addresses beyond first 64 GB.
Introduce simple identify_cpu() routine for ARM64

Add necessary cpufunction.
Detect and print:
	- implementer
	- part name
	- variant and revision
Set maximum range of physical address for EL1 mode.

Setup Intermediate Physical Address size bits in TCR_EL1 according to
PARange bits of ID_AA64MMFR0_EL1 register.