Hi srikant,
I used qmi-firmware-update to update the FW of my MC7455, it worked well. You may need to compile a recent version of libqmi yourself, though. I’m using 1.18.0. The command I used was
qmi-firmware-update --update -w /dev/cdc-wdm0 SWI9X30C_02.24.05.06.cwe SWI9X30C_02.24.05.06_GENERIC_002.026_000.nvu
https://sigquit.wordpress.com/2016/12/09/qmi-firmware-update-with-libqmi/
Jyrki