bcma: add missing includes

kbuild found out that commit 804e27de ("bcma: support bringing up
bus hosted on PCIe Gen 2") broke the build on m68k:

   drivers/bcma/driver_pcie2.c: In function 'bcma_core_pcie2_up':
>> drivers/bcma/driver_pcie2.c:196:2: error: implicit declaration of function 'pcie_set_readrq' [-Werror\
=implicit-function-declaration]
     err = pcie_set_readrq(dev, pcie2->reqsize);
     ^
   cc1: some warnings being treated as errors
Reported-by: kbuild test robot <fengguang.wu@intel.com>
Signed-off-by: Rafał Miłecki <zajec5@gmail.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>

drivers/bcma/driver_pci_host.c

@@ -11,6 +11,7 @@
 
 #include "bcma_private.h"
 #include <linux/pci.h>
+#include <linux/slab.h>
 #include <linux/export.h>
 #include <linux/bcma/bcma.h>
 #include <asm/paccess.h>

drivers/bcma/driver_pcie2.c

@@ -10,6 +10,7 @@
 
 #include "bcma_private.h"
 #include <linux/bcma/bcma.h>
+#include <linux/pci.h>
 
 /**************************************************
  * R/W ops.