cmake: libc: minimal: Move sources from 'app' to a new CMake library
cmake: libc: minimal: Move sources from 'app' to a new CMake library

The minimal libc source files have been added to 'app'. The Zephyr
build system should not be adding source files to the 'app' library
unless necessary.

This patch creates a new Zephyr CMake Library in lib/libc/minimal and
adds the sources to it.

Signed-off-by: Sebastian Bøe <edee888afd63e94916688495334700803eba20a0@nordicsemi.no>

mbolivar/zephyr,explora26/zephyr,zephyrproject-rtos/zephyr,punitvara/zephyr,zephyriot/zephyr,Vudentz/zephyr,finikorg/zephyr,GiulianoFranchetto/zephyr,galak/zephyr,finikorg/zephyr,Vudentz/zephyr,zephyriot/zephyr,punitvara/zephyr,kraj/zephyr,zephyriot/zephyr,explora26/zephyr,ldts/zephyr,finikorg/zephyr,zephyrproject-rtos/zephyr,Vudentz/zephyr,finikorg/zephyr,zephyriot/zephyr,nashif/zephyr,zephyrproject-rtos/zephyr,Vudentz/zephyr,mbolivar/zephyr,Vudentz/zephyr,GiulianoFranchetto/zephyr,ldts/zephyr,nashif/zephyr,galak/zephyr,kraj/zephyr,ldts/zephyr,zephyriot/zephyr,zephyrproject-rtos/zephyr,explora26/zephyr,kraj/zephyr,GiulianoFranchetto/zephyr,ldts/zephyr,galak/zephyr,kraj/zephyr,explora26/zephyr,nashif/zephyr,nashif/zephyr,galak/zephyr,explora26/zephyr,mbolivar/zephyr,nashif/zephyr,punitvara/zephyr,galak/zephyr,mbolivar/zephyr,mbolivar/zephyr,ldts/zephyr,Vudentz/zephyr,punitvara/zephyr,finikorg/zephyr,punitvara/zephyr,zephyrproject-rtos/zephyr,kraj/zephyr,GiulianoFranchetto/zephyr,GiulianoFranchetto/zephyr