net: lwm2m: setup lwm2m ctx for firmware download
net: lwm2m: setup lwm2m ctx for firmware download

Previously, firmware support wasn't initializing the retransmit work
or the extra network packet pools.  Let's fix that.

NOTE: While this fixes the setup of retransmit work, the actual
attempts to re-send packets which are pending is failing.  Needs
another follow-up fix.

Signed-off-by: Michael Scott <087571639a1dbb4ff1803c64e3643475ba482686@linaro.org>

GiulianoFranchetto/zephyr,ldts/zephyr,explora26/zephyr,kraj/zephyr,nashif/zephyr,aceofall/zephyr-iotos,aceofall/zephyr-iotos,finikorg/zephyr,zephyrproject-rtos/zephyr,nashif/zephyr,zephyriot/zephyr,punitvara/zephyr,kraj/zephyr,zephyrproject-rtos/zephyr,nashif/zephyr,zephyrproject-rtos/zephyr,Vudentz/zephyr,galak/zephyr,fbsder/zephyr,nashif/zephyr,punitvara/zephyr,mbolivar/zephyr,ldts/zephyr,galak/zephyr,fbsder/zephyr,punitvara/zephyr,explora26/zephyr,zephyriot/zephyr,ldts/zephyr,aceofall/zephyr-iotos,galak/zephyr,kraj/zephyr,mbolivar/zephyr,zephyriot/zephyr,nashif/zephyr,GiulianoFranchetto/zephyr,GiulianoFranchetto/zephyr,Vudentz/zephyr,explora26/zephyr,kraj/zephyr,explora26/zephyr,mbolivar/zephyr,explora26/zephyr,mbolivar/zephyr,zephyrproject-rtos/zephyr,fbsder/zephyr,galak/zephyr,fbsder/zephyr,ldts/zephyr,Vudentz/zephyr,Vudentz/zephyr,zephyriot/zephyr,ldts/zephyr,Vudentz/zephyr,zephyriot/zephyr,mbolivar/zephyr,finikorg/zephyr,punitvara/zephyr,finikorg/zephyr,fbsder/zephyr,Vudentz/zephyr,finikorg/zephyr,kraj/zephyr,aceofall/zephyr-iotos,zephyrproject-rtos/zephyr,GiulianoFranchetto/zephyr,finikorg/zephyr,punitvara/zephyr,GiulianoFranchetto/zephyr,galak/zephyr,aceofall/zephyr-iotos