libc: minimal: Add dummy sys/stat.h [REVERTME]
libc: minimal: Add dummy sys/stat.h [REVERTME]

Some third-party components include this file without really needing
any symbols from it. Presence of this file allows to build them
against minimal libc, whereas previously they forced Newlib.

Signed-off-by: Paul Sokolovsky <35cb557f011771c94f127d6fef99f804b62203f5@linaro.org>

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