pw_kvs: add move ctor to FlashPartition

Adds a move constructor to the FlashPartition to allow
instantiation of FlashPartition arrays through initializer lists.

Change-Id: I8406dd57db84f4ce7ff47e7275ce51ab97da072f
Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/pigweed/+/15661
Commit-Queue: Ewout van Bekkum <ewout@google.com>
Reviewed-by: David Rogers <davidrogers@google.com>
diff --git a/pw_kvs/public/pw_kvs/flash_memory.h b/pw_kvs/public/pw_kvs/flash_memory.h
index 2ba5ea1..6abf14a 100644
--- a/pw_kvs/public/pw_kvs/flash_memory.h
+++ b/pw_kvs/public/pw_kvs/flash_memory.h
@@ -188,6 +188,7 @@
       : FlashPartition(
             flash, 0, flash->sector_count(), flash->alignment_bytes()) {}
 
+  FlashPartition(FlashPartition&&) = default;
   FlashPartition(const FlashPartition&) = delete;
   FlashPartition& operator=(const FlashPartition&) = delete;