This removes the headers imported from the embeddedsw repository in
favor of a much thinner shim. This also removes the complicated build
system configuration necessary to support use of these headers. The
primary reason for removal is that certain external Xilinx libraries
also require use of these headers and this causes version mismatches and
header conflicts that can be avoided.
This imports the TTC hardware definitions for the triple timer counters
on various Xilinx platforms. This was imported as specified in the
VERSION file in this commit.
This breaks AArch32-specific portions of the ARM GPT driver into their
own file so that the generic code can be moved for reuse by other
architectures.
