northbridge/amd/agesa/family15tn: Sanitize #includes

NOTFORMERGE:

Following the same reasoning as commit
<HASH HERE> (pavilion) hp/pavilion_m6_1035dx: Sanitize #includes
Clean up the #include directives in this northbridge code.

Change-Id: I8e27ddb9cbd1c9e5c2f15626815875047de18a0b
Signed-off-by: Alexandru Gagniuc <mr.nuke.me@gmail.com>
southbridge/amd/agesa/hudson: Clean up AGESA #includes

NOTFORMERGE: EDIT commit message to include proper hash

Just like in commit
<HASH HERE> vendorcode/amd/agesa/fam15tn: Clean #includes in public headers

Include AGESA headers specifying the path relative to AGESA_ROOT. The
path is specified relative to AGESA_ROOT as opposed to src/ since this
code may include headers from different AGESA families, depending on
the board.

Change-Id: Ide38cc34e207a8b617d1d319fd9c17a785f55833
Signed-off-by: Alexandru Gagniuc <mr.nuke.me@gmail.com>
vendorcode/amd/agesa/fam15tn: Clean #includes in public headers

Right now, coreboot code using AGESA headers can only build if all the
AGESA path are given to the compiler via the "-I" option. This is sub-
optimal, as it requires us to have every AGESA source directory
specified as a compiler include path. This pollutes our global include
paths.

We restrict the compiler include paths to only allow "AGESA_ROOT/" and
"AGESA_ROOT/Include". We then modify the AGESA headers to specify
non-local include files relative to "AGESA_ROOT/Include".

We use the convention that includes relative to the directory of the
header are included as "path/to/header.h", while includes relative to
AGESA_ROOT are included as <path/to/header.h>.

This change allows building coreboot code based on AGESA with the
limited subset of include paths, but does not allow AGESA itself to
build with this restricted subset.

Change-Id: I31102273c8caa8d6b1d80774bfd35711825bec03
Signed-off-by: Alexandru Gagniuc <mr.nuke.me@gmail.com>
x86/Makefile: Allow addition of link libraries for rom/ramstage

This is useful, for example, when using stage-independent code, as it
allows us to compile that code only once. It's also useful for vendor
code which needs wonky compiler definitions and include paths which
we'd rather not include in the other files.

Subsequent patches will make use of this when lib-izing AGESA.

Change-Id: Ifb0c5d353bf09d23864270b9eefb6b75fd86e6cb
Signed-off-by: Alexandru Gagniuc <mr.nuke.me@gmail.com>