libfdtgen: fix string_buf overwriting

string_buf will be overwritten by recursive calls,
need to back up the string_buf before recursive calls
and free after that.

libfdtgen: reslove node deps when not present

resolve the dependency of the nodes in the path
when the dependency is not present

libfdtgen: fix keep_node_and_parents

1. reset string buffer when early exits
2. fix indent in various functions
3. resolve the dependency of the nodes on the path

libfdtgen: construct fullpath while traversing

this eliminates expensive calls to fdt_get_path

libfdtgen: performance tune

1. add compile options
2. add early exit for trim_tree
3. optimise the procedure to resolve dependency

libfdtgen: add keep and disable apis

this commit added the "keep and disable" apis, which could keep
the device nodes in-tree but disabled
this commit also improved the workflow to resolve dependency
removed the duplicated keep_node table

libfdtgen: remove debugging functions

remove the helper functions which were used during development

libfdtgen: remove arm_vm specific function

these functions are in arm_vm repo now

libfdtgen: move uthash into libutil

move uthash into libutil

libfdtgen: replace magic number with constant

replace magic number with constant

libfdtgen: add appropriate error handling

this library can now return error when failing instead of halt

libfdtgen: remove redundant memcpy

we can fdt_open_into the new buffer

libfdtgen: add documentation

1. renamed struct fdtgen to fdtgen_context
2. added documentation to the interfaces

libfdtgen: multi arch support

support 32bit and 64bit memory and chosen node generation
this commit also fixed a small memory leak when free

libfdtgen: implement OO style interfaces

removed all the usage of static variable to allow
concurrent access to this library

libfdtgen: rename d_list to to_list

rename d_list to to_list

libfdtgen: resolve power-domains dependency

resolve power-domains dependency

libfdtgen: Add more interfaces

this commit added interfaces to generate memory and chosen nodes.
this commit also fixed the resolving of clocks property dependency.

libfdtgen: remove incomplete lenp check

since clocks prop has variable length, need to think
about a way to check lenp based on prop type.

libfdtgen: fixup several things form review

1: add license tag for uthash.h
2: replace assert with ZF_LOGF
3: fix a small memory leak
4: restructure prop type check
5: fix fix print_d_node debug function

libfdtgen: initial release

this library can generate a sub-devicetree
using a root devicetree and a specification