feat: bsp: qemu-riscv64: remove useless configs

bsp/qemu-virt64-riscv/Kconfig

@@ -59,7 +59,3 @@ config ARCH_USING_NEW_CTX_SWITCH
 config __STACKSIZE__
     int "stack size for interrupt"
     default 4096
-
-config RT_USING_RV64ILP32
-    bool "Use RV64ILP32 toolchain"
-    default n