test/py: Drop u_boot_ prefix on test files

We know this is U-Boot so the prefix serves no purpose other than to
make things longer and harder to read. Drop it and rename the files.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Mattijs Korpershoek <mkorpershoek@baylibre.com> # test_android / test_dfu
diff --git a/test/py/tests/test_tpm2.py b/test/py/tests/test_tpm2.py
index 47e0e7a..ade102a 100644
--- a/test/py/tests/test_tpm2.py
+++ b/test/py/tests/test_tpm2.py
@@ -4,7 +4,7 @@
 
 import os.path
 import pytest
-import u_boot_utils
+import utils
 import re
 import time
 
@@ -197,7 +197,7 @@
         tpm2_sandbox_init(ubman)
 
     force_init(ubman)
-    ram = u_boot_utils.find_ram_base(ubman)
+    ram = utils.find_ram_base(ubman)
 
     read_cap = ubman.run_command('tpm2 get_capability 0x6 0x20e 0x200 1') #0x%x 1' % ram)
     output = ubman.run_command('echo $?')
@@ -220,7 +220,7 @@
     if is_sandbox(ubman):
         tpm2_sandbox_init(ubman)
     force_init(ubman)
-    ram = u_boot_utils.find_ram_base(ubman)
+    ram = utils.find_ram_base(ubman)
 
     # Set the DAM parameters to known values
     ubman.run_command('tpm2 dam_parameters 3 10 0')
@@ -245,7 +245,7 @@
         tpm2_sandbox_init(ubman)
 
     force_init(ubman)
-    ram = u_boot_utils.find_ram_base(ubman)
+    ram = utils.find_ram_base(ubman)
 
     read_pcr = ubman.run_command('tpm2 pcr_read 10 0x%x' % ram)
     output = ubman.run_command('echo $?')
@@ -273,7 +273,7 @@
     if is_sandbox(ubman):
         tpm2_sandbox_init(ubman)
     force_init(ubman)
-    ram = u_boot_utils.find_ram_base(ubman)
+    ram = utils.find_ram_base(ubman)
 
     read_pcr = ubman.run_command('tpm2 pcr_read 10 0x%x' % (ram + 0x20))
     output = ubman.run_command('echo $?')