libpayload: Expand doxygen definitions

Expand libpayload.h to include a main page and add individual 
groups for the API functions - this adds the Modules tab to
the doxygen output.

Specify the INPUT list rather then the EXCLUDE list of directories
to omit random .c files that we don't want.  Add clean targets to
the makefile to clean doxygen files only.

Signed-off-by: Jordan Crouse <jordan.crouse@amd.com>
Acked-by: Stefan Reinauer <stepan@coresystems.de>


git-svn-id: svn://svn.coreboot.org/coreboot/trunk@3545 2b7e53f0-3cfb-0310-b3e9-8179ed1497e1

payloads/libpayload/Doxyfile

@@ -534,7 +534,7 @@ WARN_LOGFILE           =
 # directories like "/usr/src/myproject". Separate the files or directories 
 # with spaces.
 
-INPUT                  = 
+INPUT                  = crypto curses drivers i386 include libc
 
 # This tag can be used to specify the character encoding of the source files 
 # that doxygen parses. Internally doxygen uses the UTF-8 encoding, which is 
@@ -551,7 +551,7 @@ INPUT_ENCODING         = UTF-8
 # *.c *.cc *.cxx *.cpp *.c++ *.java *.ii *.ixx *.ipp *.i++ *.inl *.h *.hh *.hxx 
 # *.hpp *.h++ *.idl *.odl *.cs *.php *.php3 *.inc *.m *.mm *.py *.f90
 
-FILE_PATTERNS          = 
+FILE_PATTERNS          = *.c *.h
 
 # The RECURSIVE tag can be used to turn specify whether or not subdirectories 
 # should be searched for input files as well. Possible values are YES and NO. 
@@ -563,7 +563,7 @@ RECURSIVE              = YES
 # excluded from the INPUT source files. This way you can easily exclude a 
 # subdirectory from a directory tree whose root is specified with the INPUT tag.
 
-EXCLUDE                = util
+EXCLUDE                =
 
 # The EXCLUDE_SYMLINKS tag can be used select whether or not files or 
 # directories that are symbolic links (a Unix filesystem feature) are excluded 
@@ -591,7 +591,7 @@ EXCLUDE_SYMBOLS        =
 # directories that contain example code fragments that are included (see 
 # the \include command).
 
-EXAMPLE_PATH           = 
+EXAMPLE_PATH           = sample
 
 # If the value of the EXAMPLE_PATH tag contains directories, you can use the 
 # EXAMPLE_PATTERNS tag to specify one or more wildcard pattern (like *.cpp