Using the vendor `memory.ld.in` instead of a static `memory.ld`, from which the actual used `memory.ld` is generated with the C preprocessor, allows to use the configuration in `sdkconfig.h` as well as Kconfig to use a custom memory layout. For example, it is no longer necessary to maintain different `memory.ld` files for the ESP32 BLE module, since the memory layout is now defined from the values of the configuration.
