config.h: clarify CONFIG_INTERNAL_STORAGE semantics
The semantics in the EC code base are that CONFIG_INTERNAL_STORAGE
implies eXecute-In-Place semantics (XIP). Add a comment to make that
abundantly clear.
BRANCH=none
TEST=none
/*
* EC code can reside on internal or external storage. Only one of these
- * CONFIGs should be defined.
+ * CONFIGs should be defined. CONFIG_INTERNAL_STORAGE implies XIP
+ * (eXecute-In-Place) semantics. i.e. code is being fetched directly from
+ * storage media.
*/
#undef CONFIG_EXTERNAL_STORAGE
#undef CONFIG_INTERNAL_STORAGE
