- update doc for different core configuration.
- fix some bugs in dts related files.
- add dts config and defconfig for different core configuration.
- end files with a newline in boards/arc/emsdp/board.dtsi
- remove unused head in boards/arc/emsdp/doc/index.rst
- ARC_MPU_VER in different core is fixed. so remove some useless code
for ARC_MPU_VER judgements in Kconfig.defconfig.* files for emsdp
Signed-off-by: Watson Zeng <zhiwei@synopsys.com>