media: ivtv: fix build for UML

media: ivtv: fix build for UML

Prevent the use of page table macros and types from 2 conflicting
places. This fixes multiple build errors and warnings, e.g.:

../arch/x86/include/asm/pgtable_64_types.h:21:34: error: conflicting types for ‘pte_t’
 typedef struct { pteval_t pte; } pte_t;
                                  ^~~~~
In file included from ../include/linux/mm_types_task.h:16:0,
                 from ../include/linux/mm_types.h:5,
                 from ../include/linux/buildid.h:5,
                 from ../include/linux/module.h:14,
                 from ../drivers/media/pci/ivtv/ivtv-driver.h:40,
                 from ../drivers/media/pci/ivtv/ivtvfb.c:29:
../arch/um/include/asm/page.h:57:39: note: previous declaration of ‘pte_t’ was here
 typedef struct { unsigned long pte; } pte_t;

../arch/x86/include/asm/pgtable_types.h:284:43: error: expected ‘)’ before ‘prot’
 static inline pgprot_t pgprot_nx(pgprot_t prot)
                                           ^
../include/linux/pgtable.h:914:26: note: in definition of macro ‘pgprot_nx’
 #define pgprot_nx(prot) (prot)
                          ^~~~
In file included from ../arch/x86/include/asm/memtype.h:6:0,
                 from ../drivers/media/pci/ivtv/ivtvfb.c:40:
../arch/x86/include/asm/pgtable_types.h:288:0: warning: "pgprot_nx" redefined
 #define pgprot_nx pgprot_nx

../arch/x86/include/asm/page_types.h:11:0: warning: "PAGE_SIZE" redefined
 #define PAGE_SIZE  (_AC(1,UL) << PAGE_SHIFT)

In file included from ../include/linux/mm_types_task.h:16:0,
                 from ../include/linux/mm_types.h:5,
                 from ../include/linux/buildid.h:5,
                 from ../include/linux/module.h:14,
                 from ../drivers/media/pci/ivtv/ivtv-driver.h:40,
                 from ../drivers/media/pci/ivtv/ivtvfb.c:29:
../arch/um/include/asm/page.h:14:0: note: this is the location of the previous definition
 #define PAGE_SIZE (_AC(1, UL) << PAGE_SHIFT)

Fixes: 68f5d3f3b654 ("um: add PCI over virtio emulation driver")
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Johannes Berg <johannes@sipsolutions.net>
Cc: Andy Walls <awalls@md.metrocast.net>
Cc: linux-um@lists.infradead.org
Cc: Richard Weinberger <richard@nod.at>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>