Fix memory allocation on STM32L4 devices
Fix memory allocation on STM32L4 devices

Depending on initial size allocated on STM32L4 devices with
TWO_RAM_REGIONS  set a crash may occur. This is because there is a
mismatch between the size newlib is expecting and the size actually
returned by _sbrk. This is because the STM32L4 implementation of _sbrk
is performing alignment internally.

This patch fixes this problem by removing the code in __wrap__sbrk
which performs the alignment.

mbedmicro/mbed,betzw/mbed-os,kjbracey-arm/mbed,betzw/mbed-os,andcor02/mbed-os,c1728p9/mbed-os,betzw/mbed-os,andcor02/mbed-os,betzw/mbed-os,mbedmicro/mbed,kjbracey-arm/mbed,kjbracey-arm/mbed,c1728p9/mbed-os,andcor02/mbed-os,c1728p9/mbed-os,andcor02/mbed-os,betzw/mbed-os,c1728p9/mbed-os,c1728p9/mbed-os,andcor02/mbed-os,mbedmicro/mbed,kjbracey-arm/mbed,c1728p9/mbed-os,mbedmicro/mbed,mbedmicro/mbed,betzw/mbed-os,andcor02/mbed-os