docs: samples: Update pyocd calls to unified tool subcommands

pyocd 0.14.0 merged its command-line tools into a unified pyocd tool
with subcommands. The separate command-line tools still remain, but are
deprecated. Update all pyocd calls in samples and documentation to use
the new unified pyocd tool with subcommands.

Note that pyocd 0.15.0 has an issue with the command 'pyocd erase',
which was fixed in pyocd 0.16.0.

Signed-off-by: Maureen Helm <maureen.helm@nxp.com>
diff --git a/docs/testplan-zephyr.md b/docs/testplan-zephyr.md
index 2f7e255..bd5b34b 100644
--- a/docs/testplan-zephyr.md
+++ b/docs/testplan-zephyr.md
@@ -20,7 +20,7 @@
 
 Begin by doing a full erase, and programming the bootloader itself:
 
-    $ pyocd-flashtool -ce
+    $ pyocd erase --chip
     $ make flash_boot
 
 After it resets, look for "main: Starting bootloader", a few debug
@@ -44,7 +44,7 @@
 
 Now reset the target::
 
-    $ pyocd-tool reset
+    $ pyocd commander -c reset
 
 And you should see a revert and "hello1" running.
 
@@ -58,8 +58,8 @@
 
 We should have just booted the hello2.  Mark this as OK:
 
-    $ pyocd-flashtool -a 0x7ffe8 image_ok.bin
-    $ pyocd-tool reset
+    $ pyocd flash -a 0x7ffe8 image_ok.bin
+    $ pyocd commander -c reset
 
 And make sure this stays in the "hello2" image.