Annotate EEPROM flashing procedure with optional erase operation first.

testplan/programrom.txt

@@ -3,6 +3,12 @@
 $ dtc -I dts -O dtb -o programrst.dtb programrst.dts
 $ ./eepmake programdat.txt programdat.eep programrst.dtb
 # now short J7 with a paperclip
-$ sudo ./eepflash.sh -w -t=24c32 -f=programdat.eep
+#
+# optionally erase EEPROM first
+$ dd if=/dev/zero ibs=1k count=4 of=blank.eep
+$ hexdump blank.eep
+# ./eepflash.sh -w -t=24c32 -f=blank.eep
+#
+# ./eepflash.sh -w -t=24c32 -f=programdat.eep
 # to clean binaries, rm programdat.eep programrst.dtb
 # to test reboot, blue button, and sendcommrst.sh