SAMD21: set the filesystem type to LFS1.
SAMD51: the type is already set to LFS2, support is now dropped for LFS1.
It has not been used and dropping it saves 10 k of flash.
Signed-off-by: robert-hh <robert@hammelrath.com>
Remove two SPARKFUN_SAMD51_THINGS_PLUS pin definitions. There were
definitions of TXD and RXD, but these pins do not exist on the board. They
were only shown in the schematics.
Also remove any reference to LED_. This is just a text change, no
functional change.