This changes the prefixes of the symbols generated from USEMODULE and
USEPKG variables. The changes are as follow:
KCONFIG_MODULE_ => KCONFIG_USEMODULE_
KCONFIG_PKG_ => KCONFIG_USEPKG_
MODULE_ => USEMODULE_
PKG_ => USEPKG_
SD cards are usually larger than 4 GiB, so using 32 bit addressing will
break once they are filled to a certain extend.
Implement read_page() and write_page() which at a page size of 512
should work for SD cards of up to 2 TiB.
The read() and write() functions will ignore any offset that is not aligned
with the page boundary, so do the same for the new functions, but at least
report an error.
