arch: arm64: dts: disable fcs feature by default on Intel socfpga platforms

FCS(FPGA Crypto Service) feature is a part of securityfunction,
To enable it,  special QKY key file needs to be loaded into FPGA
project with Quartus tool, and then signs FPGA image. The standard
FPGA image doesn't support FCS feature, so disable it by default in
standard dts file. In later, a secure related dts file with fcs
feature will be created if necessary.

Signed-off-by: Meng Li <Meng.Li@windriver.com>
Signed-off-by: Bruce Ashfield <bruce.ashfield@gmail.com>
[Only disable fcs for s10 since we have supported it on agl board]
Signed-off-by: Liwei Song <liwei.song@windriver.com>