parisc: move definition of PAGE0 to asm/page.h

This was defined in asm/pdc.h which needs to include asm/page.h for
__PAGE_OFFSET. This leads to an include loop so that page.h eventually will
include pdc.h again. While this is no problem because of header guards, it is
a problem because some symbols may be undefined. Such an error is this:

In file included from include/linux/bitops.h:35:0,
                 from include/asm-generic/getorder.h:7,
                 from arch/parisc/include/asm/page.h:162,
                 from arch/parisc/include/asm/pdc.h:346,
                 from arch/parisc/include/asm/processor.h:16,
                 from arch/parisc/include/asm/spinlock.h:6,
                 from arch/parisc/include/asm/atomic.h:20,
                 from include/linux/atomic.h:4,
                 from include/linux/sysfs.h:20,
                 from include/linux/kobject.h:21,
                 from include/linux/device.h:17,
                 from include/linux/eisa.h:5,
                 from arch/parisc/kernel/pci.c:11:
arch/parisc/include/asm/bitops.h: In function ‘set_bit’:
arch/parisc/include/asm/bitops.h:82:2: error: implicit declaration of function ‘_atomic_spin_lock_irqsave’ [-Werror=implicit-function-declaration]
arch/parisc/include/asm/bitops.h:84:2: error: implicit declaration of function ‘_atomic_spin_unlock_irqrestore’ [-Werror=implicit-function-declaration]

Signed-off-by: Rolf Eike Beer <eike-kernel@sf-tec.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/drivers/parisc/sba_iommu.c b/drivers/parisc/sba_iommu.c
index 8644d53..42cfcd9 100644
--- a/drivers/parisc/sba_iommu.c
+++ b/drivers/parisc/sba_iommu.c
@@ -44,6 +44,7 @@
 #include <asm/ropes.h>
 #include <asm/mckinley.h>	/* for proc_mckinley_root */
 #include <asm/runway.h>		/* for proc_runway_root */
+#include <asm/page.h>		/* for PAGE0 */
 #include <asm/pdc.h>		/* for PDC_MODEL_* */
 #include <asm/pdcpat.h>		/* for is_pdc_pat() */
 #include <asm/parisc-device.h>