nokia3310: support more recent TLS8202 based boards.

Later versions of the Nokia 3310 display, including the one sold by Olimex, have a different but mostly compatible driver chip.  This patch updates the driver to use the subset of commands understood by both generations of the screen.

Unfortunately I don't have a Philips based screen to test on.  I'm pretty sure it'll work.

Also bump the default SPI speed so fbtft works out of the box with AT91G25 processors.