docs: kgdb: Fix stale source file paths

Update two file paths that became stale when kgdb/kdb sources
were reorganized:
- kernel/debugger/debug_core.c -> kernel/debug/debug_core.c
- drivers/char/kdb_keyboard.c -> kernel/debug/kdb/kdb_keyboard.c

Assisted-by: Claude:claude-opus-4-6
Signed-off-by: Costa Shulyupin <costa.shul@redhat.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Message-ID: <20260531140207.4114764-1-costa.shul@redhat.com>

Author: makelinux

Documentation/process/debugging/kgdb.rst

@@ -696,7 +696,7 @@ The kernel debugger is organized into a number of components:
 
 1. The debug core
 
-   The debug core is found in ``kernel/debugger/debug_core.c``. It
+   The debug core is found in ``kernel/debug/debug_core.c``. It
    contains:
 
    -  A generic OS exception handler which includes sync'ing the
@@ -877,7 +877,7 @@ attached keyboard. The keyboard infrastructure is only compiled into the
 kernel when ``CONFIG_KDB_KEYBOARD=y`` is set in the kernel configuration.
 
 The core polled keyboard driver for PS/2 type keyboards is in
-``drivers/char/kdb_keyboard.c``. This driver is hooked into the debug core
+``kernel/debug/kdb/kdb_keyboard.c``. This driver is hooked into the debug core
 when kgdboc populates the callback in the array called
 :c:expr:`kdb_poll_funcs[]`. The kdb_get_kbd_char() is the top-level
 function which polls hardware for single character input.