test/py: Manual python3 fixes

- Modern pytest is more visible in telling us about parameters that we
  had not described, so describe a few more.
- ConfigParser.readfp(...) is now configparser.read_file(...)
- As part of the "strings vs bytes" conversions in Python 3, we use the
  default encoding/decoding of utf-8 but in some places tell Python to
  replace problematic conversions rather than throw a fatal error.
- Fix a typo noticed while doing the above ("tot he" -> "to the").
- As suggested by Stephen, re-alphabetize the import list
- Per Heinrich, replace how we write contents in test_fit.py

Reviewed-by: Simon Glass <sjg@chromium.org>
Tested-by: Stephen Warren <swarren@nvidia.com>
Tested-by: Simon Glass <sjg@chromium.org> [on sandbox]
Signed-off-by: Tom Rini <trini@konsulko.com>

test/py/tests/test_fit.py

@@ -153,7 +153,7 @@ def test_fit(u_boot_console):
         src = make_fname('u-boot.dts')
         dtb = make_fname('u-boot.dtb')
         with open(src, 'w') as fd:
-            print(base_fdt, file=fd)
+            fd.write(base_fdt)
         util.run_and_log(cons, ['dtc', src, '-O', 'dtb', '-o', dtb])
         return dtb
 
@@ -186,7 +186,7 @@ def test_fit(u_boot_console):
         its = make_its(params)
         util.run_and_log(cons, [mkimage, '-f', its, fit])
         with open(make_fname('u-boot.dts'), 'w') as fd:
-            print(base_fdt, file=fd)
+            fd.write(base_fdt)
         return fit
 
     def make_kernel(filename, text):