Change all time conversions.  Yech.  New timer units in microseconds breaks all existing logic that used milliseconds in the conversions.  Something likely got broken doing this, probably because I confused a MSEC2TICK conversion with a TICK2MSEC conversion.  Also, the tickless OS no appears fully functional and passes the OS test on the simulator with no errors

Change CONFIG_MSEC_PER_TICK to CONFIG_USEC_PER_TICK.  This gives more options for system timers in general, but more importantly, let's us realize higher resolution for the case of CONFIG_SCHED_TICKLESS=y -- of course, at the risk of some new interger overvflow problems

Rename up_timerinit() to up_timer_initailize(); Add prototypes for candidate interfaces for the tickless OS; Don't build existing timer initialization logic if CONFIG_SCHED_TICKLESS is defined.

WM8904 interface enable method now returns the previous interrupt state.  Correct ordering of some WM8904: Need to provide MCLK before initializing the WM8904, not after

WM8904:  Ad the MCLK frequency to the interface definition.  The WM8904 driver needs to know this frequency in order to configure the FLL to generate the correct bitrate

dd support for a USB keyboard as the NxConsole and text widget input.  Not fully functional as of this initial check-in.  Basic functionality is there, but there are conditions were the keyboard gets lost.

SAMA5 HSMCI: e-enable TX DMA and verify that DMA writes to the SD card are functional.  They are so now TX DMA is re-enabled in the driver.  This might affect the SAMA5D3 platforms where the TX DMA problem was found.  The SAMA4D3 and 4 use the same HSMCI driver.  Much has change since then and it is not surprising that DMA is now functional.  However, the has not be re-verified on the SAMA5D3 which has a different DMA controller.

The SAMA5D4-EK NSH and NxWM configurations now have the auto-mounter configured to automatically mount the FAT file system on HSMCI0 at /mnt/sdcard