hdf2arch.pl: initial commit (processor, memory)

The utility hdf2arch.pl read the Hardware Description File from the
Epiphany SDK and generates a DOL architecture specification in XML format.

example:
$ ./hdf2arch.pl zed_E16G3_512mb.hdf epiphany.xml

This specifies the <processor> and <memory> elements for every eCore in the
Epiphany (called "core_row_col" and "mem_row_col") as well as for the
host cpu and the shared DRAM (called "arm_0" and "shm_0") and includes
some basic sanity checking of the HDF.

The generated file does not specify any <hw_channel>, <writepath> or
<readpath> tags and does not need any flattening.

Since the HDF file does not contain any information about the amount
of local SRAM or even the number of cores in the Epiphany, new chips
will need to be added to this utility. The ARM (with 2 cores) is hard coded,
though.