Allow enabling libc netdb support via menuconfig

[tuupola]

Summary

This PR allows enabling libc netdb support via make <target> menuconfig. The PR adds a checkbox under NETDB Support menu by adding a prompt to an existing config item. This is allows fixing PX4/PX4-Autopilot#25540 and PX4/PX4-Autopilot#24273.

Impact

Allow compiling with uxrce_dds_client support enabled which requires freeaddrinfo() and friends but with minimal changes to NuttX fork itself.

Testing

Fresh checkout fails.

$ make micoair_h743-v2_default -j8
...
/home/tuupola/Code/c/PX4-Autopilot/src/modules/uxrce_dds_client/Micro-XRCE-DDS-Client/src/c/profile/transport/ip/udp/udp_transport_posix.c:57:13: error: implicit declaration of function 'freeaddrinfo' [-Wimplicit-function-declaration]
   57 |             freeaddrinfo(result);
      |             ^~~~~~~~~~~~
ninja: build stopped: subcommand failed.
...

After enabling libc netdb support compilation succeeds.

$ make micoair_h743-v2 menuconfig

$ git diff boards/micoair/h743-v2/nuttx-config/nsh/defconfig
diff --git a/boards/micoair/h743-v2/nuttx-config/nsh/defconfig b/boards/micoair/h743-v2/nuttx-config/nsh/defconfig
index dab70e35fa..3945e6a2b0 100644
--- a/boards/micoair/h743-v2/nuttx-config/nsh/defconfig
+++ b/boards/micoair/h743-v2/nuttx-config/nsh/defconfig
@@ -118,6 +118,7 @@ CONFIG_IOB_NCHAINS=24
 CONFIG_LIBC_FLOATINGPOINT=y
 CONFIG_LIBC_LONG_LONG=y
 CONFIG_LIBC_MAX_EXITFUNS=1
+CONFIG_LIBC_NETDB=y
 CONFIG_LIBC_STRERROR=y
 CONFIG_MEMSET_64BIT=y
 CONFIG_MEMSET_OPTSPEED=y

$ make micoair_h743-v2_default -j8
...
Memory region         Used Size  Region Size  %age Used
        ITCM_RAM:           0 B        64 KB      0.00%
           FLASH:     1903296 B      1920 KB     96.81%
       DTCM1_RAM:           0 B        64 KB      0.00%
       DTCM2_RAM:           0 B        64 KB      0.00%
        AXI_SRAM:       52088 B       512 KB      9.93%
           SRAM1:           0 B       128 KB      0.00%
           SRAM2:           0 B       128 KB      0.00%
           SRAM3:           0 B        32 KB      0.00%
           SRAM4:           0 B        64 KB      0.00%
          BKPRAM:           0 B         4 KB      0.00%