fixes warning: rtthread.elf has a LOAD segment with RWX permissions

c:/env-windows/tools/gnu_gcc/riscv64-linux-musleabi_for_i686-w64-mingw32/bin/../lib/gcc/riscv64-linux-musleabi/12.2.0/../../../../riscv64-linux-musleabi/bin/ld.exe: warning: rtthread.elf has a LOAD segment with RWX permissions

The warning is present when using:
gcc version 12.2.0 (GCC)

Author: lygstate

bsp/qemu-virt64-riscv/rtconfig.py

@@ -35,7 +35,7 @@
     DEVICE  = ' -mcmodel=medany -march=rv64imafdc -mabi=lp64 '
     CFLAGS  = DEVICE + '-ffreestanding -flax-vector-conversions -Wno-cpp -fno-common -ffunction-sections -fdata-sections -fstrict-volatile-bitfields -fdiagnostics-color=always'
     AFLAGS  = ' -c' + DEVICE + ' -x assembler-with-cpp -D__ASSEMBLY__ '
-    LFLAGS  = DEVICE + ' -nostartfiles -Wl,--gc-sections,-Map=rtthread.map,-cref,-u,_start -T link.lds' + ' -lsupc++ -lgcc -static'
+    LFLAGS  = DEVICE + ' -nostartfiles -Wl,--no-warn-rwx-segments -Wl,--gc-sections,-Map=rtthread.map,-cref,-u,_start -T link.lds' + ' -lsupc++ -lgcc -static'
     CPATH   = ''
     LPATH   = ''