[Bluetooth] Kill duplicate includes

This patch removes the duplicate inclusion of linux/config.h in the
hci_uart driver.

Patch from Arthur Othieno <a.othieno@bluewin.ch>

drivers/bluetooth/hci_bcsp.c

@@ -33,7 +33,6 @@
 #include <linux/config.h>
 #include <linux/module.h>
 
-#include <linux/config.h>
 #include <linux/kernel.h>
 #include <linux/init.h>
 #include <linux/sched.h>

drivers/bluetooth/hci_ldisc.c

@@ -32,7 +32,6 @@
 #include <linux/config.h>
 #include <linux/module.h>
 
-#include <linux/config.h>
 #include <linux/kernel.h>
 #include <linux/init.h>
 #include <linux/sched.h>