net/lldp: Switch LLDP to new net_pkt API
net/lldp: Switch LLDP to new net_pkt API

Minor changes:
- allocator needed to be changed
- and writing the lldp_pdu as well

Signed-off-by: Tomasz Bursztyka <ba81a3a719836727e6857ae83462b9f52ec41006@linux.intel.com>

nashif/zephyr,Vudentz/zephyr,galak/zephyr,explora26/zephyr,finikorg/zephyr,nashif/zephyr,zephyrproject-rtos/zephyr,Vudentz/zephyr,GiulianoFranchetto/zephyr,finikorg/zephyr,ldts/zephyr,ldts/zephyr,galak/zephyr,Vudentz/zephyr,GiulianoFranchetto/zephyr,explora26/zephyr,finikorg/zephyr,galak/zephyr,zephyrproject-rtos/zephyr,nashif/zephyr,GiulianoFranchetto/zephyr,zephyrproject-rtos/zephyr,ldts/zephyr,zephyrproject-rtos/zephyr,ldts/zephyr,Vudentz/zephyr,galak/zephyr,ldts/zephyr,Vudentz/zephyr,zephyrproject-rtos/zephyr,GiulianoFranchetto/zephyr,GiulianoFranchetto/zephyr,explora26/zephyr,explora26/zephyr,explora26/zephyr,Vudentz/zephyr,nashif/zephyr,nashif/zephyr,finikorg/zephyr,galak/zephyr,finikorg/zephyr