riscv: Remove redundant Kconfig "RISCV_NDS_CACHE"

There is no need for RISCV_NDS_CACHE config to control cache switches.

Signed-off-by: Leo Yu-Chi Liang <ycliang@andestech.com>
Reviewed-by: Yu Chien Peter Lin <peterlin@andestech.com>
Reviewed-by: Rick Chen <rick@andestech.com>
3 files changed