LoongArch: fix compile error when using make allmodconfig

LoongArch inclusion
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I6LL93

----------------------------------------
1. when compiling at arm32 using make allmodconfig,error occurred
  caused by no including the required header file, so force to
  include the required file.
2. fix drivers/vfio/pci/vfio_pci_rdwr.c compile error on LoongArch
Signed-off-by: NZheng Zengkai <zhengzengkai@huawei.com>
Signed-off-by: NHongchen Zhang <zhanghongchen@loongson.cn>
(cherry picked from commit 028c67cc)

arch/loongarch/include/asm/io.h

@@ -41,7 +41,7 @@ static inline void __iomem *ioremap_prot(phys_addr_t offset, unsigned long size,
 #define ioremap(offset, size)		\
 	ioremap_prot((offset), (size), pgprot_val(PAGE_KERNEL_SUC))
 
-#define iounmap(addr) 			do { } while (0)
+#define iounmap(addr)	((void)(addr))
 
 #endif
 

drivers/gpu/drm/loongson/lsdc_i2c.c

@@ -9,6 +9,7 @@
  */
 
 #include <linux/i2c.h>
+#include <linux/io.h>
 
 #include <drm/drm_print.h>
 #include <drm/drm_device.h>