Checks version of pip before checking pyocd

Experimental change to make sure the version of pyocd is up-to-date as it can
possibly be.

Change-Id: I437cfbaa01b56b8d094cd706f3956f6c81d21176
Signed-off-by: Matthew Dalzell <matthew.dalzell@arm.com>
diff --git a/build_helper/build_helper_configs.py b/build_helper/build_helper_configs.py
index 6ee266e..0f04d75 100755
--- a/build_helper/build_helper_configs.py
+++ b/build_helper/build_helper_configs.py
@@ -142,8 +142,9 @@
                                           "image_signing/scripts/tfm_ns_signed.bin ;"
                                           "popd"),
                    "nxp/lpcxpresso55s69": ("echo 'LPCXpresso55S69 board post process\n';"
+                                           "python3 -m pip install --upgrade pip; "
                                            "pip3 install --upgrade pyocd; "  # this is experimental, remove
-                                           "pyocd erase --mass -t LPC55S69 ; "
+                                           "pyocd erase --mass -t LPC55S69 --no-wait; "
                                            "if [ -f \"%(ci_build_root_dir)s/spe/bin/bl2.hex\" ]; then "
                                            "pyocd flash %(ci_build_root_dir)s/spe/bin/bl2.hex -t LPC55S69; "
                                            "pyocd flash %(ci_build_root_dir)s/nspe/bin/tfm_s_ns_signed.bin --base-address 0x8000 -t LPC55S69 --no-wait; "