[arch][arm-m] fix the arm_cm_priority routines to return values in the right range

NVIC_SetPriority and friends actually expect values from 0-N where N is
the max priority based on number of implemented bits (usually 7, for 3
bits).

Fix this, which actually fixes a rare bug where the systick interrupt
would preempt a regular irq.
[arch][arm-m] fix arch_cycle_count on cortex-m

A bad #ifdef broke it somewhere along the line.
[app][stringtests] add new assembly implementation of memcpy and memset for arm-m

Cortex-m devices like data to be moved in units of 64bit, but must be aligned.
Otherwise, moving a 32bit word at a time is fine at any alignment.
[lib][libc][arm-m] add new arm-m optimized memcpy and memset routines
[platform][stellaris] print more revision info

Also fixes a bug in the old revision print.
[lib][console] switch the integer args to long types
[warnings] knock out some 64bit warnings
[platform][lpc15xx] first stab at lpc15xx platform and target

Port to lpcexpresso 1549 board.
Builds, but not tested.
[platform][lpc15xx] import of lpcopen driver library

Version 2.08 of the library for lpc15xx
[platform][lpc15xx] add script and code to sign lk.bin

LPC wants you to stuff a checksum in the 8th vector slot.
[target][lpcexpresso1549] added target init code from lpcopen example code

Initialize the board and move some of the uart initialization into platform space.
[platform][lpc15xx] add irq vector table
[platform][lpc15xx] have the debug uart routine be interrupt driven on rx path
stm32f4-discovery: close port of stm32-p407

For the discovery dev board. Because it's pretty sweet.
Merge pull request #18 from machinaut/master

stm32f4-discovery: close port of stm32-p407
Merge pull request #17 from macpaul/master

Trying to enable usb support and fix compiling problem for am335x
[target][stm32f4-discovery] set HSE_VALUE to 8Mhz
[arch][arm-m] refactor systick code into separate module

Add generic support for running systick in monotonic mode and providing
current_time() routines.

Platforms may choose not to use this, thus it is moved into an optional
module.
[platform][stellaris] convert to generic systick mechanism
[platform][lpc15xx] convert to new generic systick timer mechanism