LOSTANDFOUND.md: update with boards/nrf6310

LOSTANDFOUND.md

@@ -287,6 +287,18 @@ Author(s):
 Reason for removal:
 - Hardware not available so can't be tested
 
+### boards/nrf6310 [4953ba8e6759d2b1a1a1ea497a4ad1e71489195a]
+Author(s):
+- Christian Kühling <[email protected]>
+- Timo Ziegler <[email protected]>
+- Hauke Petersen <[email protected]>
+
+Reason for removal:
+- this was an early development board by Nordic which was discontinued
+ (successor: `nrf51dk`)
+- also for a `BLE DEVKIT.N` board from Mommosoft, which was discontinued as well
+- no hardware available anymore for testing, many exclusions from CI
+
 [d83d08f0995a88f399e70a7d07b44dd780082436]: https://github.com/RIOT-OS/RIOT/commit/d83d08f0995a88f399e70a7d07b44dd780082436
 [cdc252ab7bd4161cc046bf93a3e55995704b24d4]: https://github.com/RIOT-OS/RIOT/commit/cdc252ab7bd4161cc046bf93a3e55995704b24d4
 [ed3887ac5c1e95308c2827bce3cdca8b0f146c22]: https://github.com/RIOT-OS/RIOT/commit/ed3887ac5c1e95308c2827bce3cdca8b0f146c22
@@ -317,3 +329,4 @@ Reason for removal:
 [cab1ea66b49e3c72e2827c8686c09d84ae3ef9a9]: https://github.com/RIOT-OS/RIOT/commit/cab1ea66b49e3c72e2827c8686c09d84ae3ef9a9
 [fe941ac9fe3f81c0f08ff3b8564cf439639abcda]: https://github.com/RIOT-OS/RIOT/commit/fe941ac9fe3f81c0f08ff3b8564cf439639abcda
 [81458c8eed8949c686d5ded652dbee10748e860b]: https://github.com/RIOT-OS/RIOT/commit/81458c8eed8949c686d5ded652dbee10748e860b
+[4953ba8e6759d2b1a1a1ea497a4ad1e71489195a]: https://github.com/RIOT-OS/RIOT/commit/4953ba8e6759d2b1a1a1ea497a4ad1e71489195a