Improved test suite, now features a MTD device test
Remove outdated configs, clean up pwm limit compilation
mtd: use new MTDIOC_SETSPEED ioctl

set SPI speed to 10MHz
mtd: added "mtd readtest" and "mtd rwtest"

this allows for verification of MTD operation on startup
Teached MTD test how to write back 0xFF after destructive test
Merge remote-tracking branch 'upstream/master'