configs/olimex-stm32-p407: Various changes as necessary to get the new kelf configuration working.
configs/olimex-stm32-p407: Add kernel ELF (kelf) configuration.
arch/arm: Remove support for CONFIG_ARMV7M_CMNVECTOR. It is now the only vector support available. Also remove CONFIG_HAVE_CMNVECTOR. That no longer signifies anything."
arch/arm/src/stm32: This commit removes support for the dedicated vector handling from the STM32 architecture support. Only common vectors are now supported.