[BSP] Update configuration of qemu-vexpress

bsp/qemu-vexpress-a9/.config

@@ -151,7 +151,7 @@ CONFIG_RT_USING_WDT=y
 CONFIG_RT_USING_LIBC=y
 CONFIG_RT_USING_PTHREADS=y
 CONFIG_RT_USING_POSIX=y
-# CONFIG_RT_USING_POSIX_MMAP is not set
+CONFIG_RT_USING_POSIX_MMAP=y
 CONFIG_RT_USING_POSIX_TERMIOS=y
 
 #

bsp/qemu-vexpress-a9/rtconfig.h

@@ -140,7 +140,7 @@
 #define RT_USING_LIBC
 #define RT_USING_PTHREADS
 #define RT_USING_POSIX
-/* RT_USING_POSIX_MMAP is not set */
+#define RT_USING_POSIX_MMAP
 #define RT_USING_POSIX_TERMIOS
 
 /* Network stack */