Clang version used by ARCMWDT does not support -fno-pic and -fno-pie
flags.
Flags were added into arcmwdt branch by
commit 8259931f ("xcc-clang: Do not used unavailable options").
Initially they were set in common CMakeLists.txt via
zephyr_cc_option() function, which filtered them out, and they
did not used in builing process.

Signed-off-by: Nikolay Agishev <agishev@synopsys.com>