MAINTAINERS: Add build_all test files for bbram and flash

Add build_all to `files:` entry to bbram and flash.

Signed-off-by: TOKITA Hiroshi <tokita.hiroshi@gmail.com>

MAINTAINERS.yml

@@ -1049,6 +1049,7 @@ Release Notes:
     - yperess
   files:
     - tests/drivers/bbram/
+    - tests/drivers/build_all/bbram/
     - drivers/bbram/
     - include/zephyr/drivers/bbram.h
     - doc/hardware/peripherals/bbram.rst
@@ -1401,6 +1402,7 @@ Release Notes:
     - doc/hardware/peripherals/flash.rst
     - include/zephyr/drivers/flash/
     - tests/drivers/flash_simulator/
+    - tests/drivers/build_all/flash/
   labels:
     - "area: Flash"
   tests: