linker: arm: add stm32 ccm sections

The STM32 has special Core Coupled Memory, ccm for short, that can
only be accessed through the CPU and can not be use for DMA.

The following 3 sections have been added.
- ccm_bss for zero initialized data
- ccm_data for initialized data
- ccm_noinit for uninitialized data

Signed-off-by: Erwin Rol <erwin@erwinrol.com>