cpu/stm32: optimized definition of CPUID_ADDR

cpu/stm32_common/include/periph_cpu_common.h

cpu/stm32f0/include/periph_cpu.h

cpu/stm32f0/ldscripts/stm32f030r8.ld

cpu/stm32f0/ldscripts/stm32f031k6.ld

cpu/stm32f0/ldscripts/stm32f042k6.ld

cpu/stm32f0/ldscripts/stm32f051r8.ld

cpu/stm32f0/ldscripts/stm32f070rb.ld

cpu/stm32f0/ldscripts/stm32f072rb.ld

cpu/stm32f0/ldscripts/stm32f091rc.ld

cpu/stm32f1/include/periph_cpu.h

cpu/stm32f1/ldscripts/stm32f103c8.ld

cpu/stm32f1/ldscripts/stm32f103cb.ld

cpu/stm32f1/ldscripts/stm32f103cb_opencm904.ld

cpu/stm32f1/ldscripts/stm32f103cb_sparkcore.ld

cpu/stm32f1/ldscripts/stm32f103rb.ld

cpu/stm32f1/ldscripts/stm32f103re.ld

cpu/stm32f2/include/periph_cpu.h

cpu/stm32f2/ldscripts/stm32f205rg.ld

cpu/stm32f2/ldscripts/stm32f207zg.ld

cpu/stm32f2/ldscripts/stm32f215rg.ld