[JetPack-4.6] fixes for the --no-flash command not works on Xavier-NX

hi all,

here’s bug fix for r32.6.1 to correct --no-flash and also -k partition update not works on Xavier NX series.
if you execute the pipeline as below.
$ sudo ./flash.sh -r --no-flash -k kernel jetson-xavier-nx-devkit-emmc mmcblk0p1
you’ll see the failure as following,

Error: Return value 19
Command tegrabct_v2 --chip 0x19 0 --ratchet_blob ratchet_blob.bin --minratchet tegra194-mb1-bct-ratchet-p3668.cfg
l4t_sign_image.sh: Error: Unable to find the signed file generated by tegraflash.py

it’s due to the ratchet_config is needed for signing process which flashing individual partition.
here’s bug fix to copy minratchet config over when flashing individual partition.
please revise flash.sh as below.
for example,

diff --git a/scripts/flash.sh b/scripts/flash.sh
index 35aae1e..ee74156 100755
--- a/scripts/flash.sh
+++ b/scripts/flash.sh
@@ -2095,7 +2095,7 @@ if [ "${BINSARGS}" != "" ]; then
                BCTARGS+="--uphy_config ${uphy_configname} ";
        # shellcheck disable=SC2154
-       if [ "${minratchet_config}" != "" ] && [ "${target_partname}" = "" ]; then
+       if [ "${minratchet_config}" != "" ]; then