This commit updates the visibility of various header files and cleans up
some unnecessary inclusions. Also, this commit removes certain header
include paths which were maintained for backward compatibility.
* Target components pull in xtensa component directly
* Use CPU HAL where applicable
* Remove unnecessary xtensa headers
* Compilation changes necessary to support non-xtensa gcc types (ie int32_t/uint32_t is no
longer signed/unsigned int).
Changes come from internal branch commit a6723fc