Stellaris: Do not use a loop for writing the address in LPC cycle

Eliminating the loop overhead gives a significant increase in speed. Bulk
read throughput is increased by about 40%.

Signed-off-by: Alexandru Gagniuc <mr.nuke.me@gmail.com>
Stellaris: Use stronger drive setting for LPC pins

Signed-off-by: Alexandru Gagniuc <mr.nuke.me@gmail.com>
qiprog_lpc: Avoid awkward pointer casts in favor of bit-shifts

Signed-off-by: Alexandru Gagniuc <mr.nuke.me@gmail.com>
Stellaris: Do not rely on stdio for debug console

Do not assume that we will be able to override _write and send stdio to the
UART. Instead, use vsnprintf, and directly send debug data to the UART.

Signed-off-by: Alexandru Gagniuc <mr.nuke.me@gmail.com>
Stellaris: Change LPC code to use pinout in hardware rev 0.1

Hardware revision 0.1 uses a different pinout than the original prototype.
Adjust the LPC IO code to use the new pinout.

Signed-off-by: Alexandru Gagniuc <mr.nuke.me@gmail.com>