Simplify the assignment of memory to virtual machines by requiring a single
command line option "-m <memsize in MB>" to specify the memory size.

Prior to this change the user needed to explicitly specify the amount of
memory allocated below 4G (-m <lowmem>) and the amount above 4G (-M <highmem>).

The "-M" option is no longer supported by 'bhyveload' and 'bhyve'.

The start of the PCI hole is fixed at 3GB and cannot be directly changed
using command line options. However it is still possible to change this in
special circumstances via the 'vm_set_lowmem_limit()' API provided by
libvmmapi.

Submitted by:	Dinakar Medavaram (initial version)
Reviewed by:	grehan
Obtained from:	NetApp
Add preliminary support for IBM/Lenovo TrackPoint.

PR:		kern/147237 (based on the initial patch for 8.x)
Tested by:	glebius (device detection and suspend/resume)
MFC after:	1 month