Add an example using the RTC to help with a lower power design. This is
a sister example to the existing "button-irq-printf", which is
functionally identical, but uses far less power.
There's more tricks that can be done to lower the power even further,
but this shows a few of the early steps that can be done, using the RTC
wakeup instead of a timer.
Only add one linker script per eval board, and have the Makefiles use that.
This avoids duplication, and various copy-paste errors and left-overs
which we already have in the tree.
Some of the linker scripts are not really correct, yet. Both, the comments
which say which board, chip, and RAM/ROM sizes are used, as well as the
actual RAM/ROM size definitions are sometimes copy-pasted from other boards
and are thus incorrect. This needs to be fixed.
