riscv: fix reserved memory setup
This is an automated ID intended to aid in discovery of potential security vulnerabilities. The actual impact and attack plausibility have not yet been proven. This ID is fixed in Linux Kernel version v5.10.155 by commit 94ab8f88feb75e3b1486102c0c9c550f37d9d137, it was introduced in version v5.4 by commit 922b0375fc93fb1a20c5617e37c389c26bbccb70. For more details please see the references link.