MFC 263631, 263637, 263664, 263676, 263679, 263698, 263711,

  Implement __flt_rounds for ARMv6 hard-float. The fpscr register stores the
  current rounding mode used by the VFP unit.

  Simplify how we build MACHINE_ARCH. There are 3 options that may be set
  however only arm, armeb, armv6, and soon armv6hf will be used.

  Add the llvm/clang patch for r263619.

  Reorder the pmap macros so "ARM_MMU_V6 + ARM_MMU_V7" is first. As they are
  identical this allows us to build for both v6 and v7 together.

  Add code for enabling second CPU core for A20 SoC.
  Enable SMP on Cubieboard2.

  Switch to freebsd.org emal address in copyright.
Adds the ADC driver for TI AM3xxx SoC family.

The ADC has a 12bit resolution and its raw output can be read via sysctl(8)
interface.

The driver allows the setup of ADC clock, samples average and open delay
(the number of clock cycles to wait before start the conversion).

The TSC_ADC module is set in the general purpose mode (no touchscreen
support).

Tested on Beaglebone-black.

Written based on AM335x TRM.
MFC 259641,259863,259924,259937,259961,259978,260380,260383,260410,260466,
260531,260532,260550,260619,261170,261453,261621,263280,263290,264516:
Add support for local APIC hardware-assist.
- Restructure vlapic access and register handling to support hardware-assist
  for the local APIC.
- Use the 'Virtual Interrupt Delivery' and 'Posted Interrupt Processing'
  feature of Intel VT-x if supported by hardware.
- Add an API to rendezvous all active vcpus in a virtual machine and use
  it to support level triggered interrupts with VT-x 'Virtual Interrupt
  Delivery'.
- Use a cheaper IPI handler than IPI_AST for nested page table shootdowns
  and avoid doing unnecessary nested TLB invalidations.

Reviewed by:	neel
MFC r265013

Revert r258678.  Make the led gpio-specifier match again the #gpio-cells
settings from the GPIO controller, which i had broken in r258678.  Restore
the active-low flag.