linux-yocto/5.10: qemuriscv32.cfg: RV32 only supports 1G physical memory

Integrating the following commit(s) to linux-yocto/5.10:

    a19886b00ea qemuriscv32.cfg: RV32 only supports 1G physical memory

Signed-off-by: Khem Raj <raj.khem@gmail.com>
Signed-off-by: Bruce Ashfield <bruce.ashfield@gmail.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>