net: lwm2m: relocate/memory align notification_attrs struct
net: lwm2m: relocate/memory align notification_attrs struct

For code clarity, let's move notification_attrs structure to the top
of lwm2m_engine.c.  While we're at it, we can re-order it's members
for memory alignment.

NOTE: This patch does not change the current flash or SRAM usage but
further additions to the notification_attrs structure could.

Signed-off-by: Michael Scott <17b9e1c64588c7fa6419b4d29dc1f4426279ba01@opensourcefoundries.com>

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