Rename the struct to match the function prefix and filenames.

Signed-off-by: Simon Glass <sjg@chromium.org>

This adds a test to ensure that puts is equivalent to putc called in a
loop. We don't verify the contents of the message to avoid having to
record console output a second time (though that could be added in the
future). The globals are initialized to non-zero values to avoid a
warning; in particular, the character count is off-by-one (but we always
make relative measurements).

Signed-off-by: Sean Anderson <sean.anderson@seco.com>
Reviewed-by: Simon Glass <sjg@chromium.org>

Move this struct into a header file so that dtoc can include it in its
dt-platdata.c file.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>