powerpc/powernv: Specify proper data type for PCI_SLOT_ID_PREFIX

This fixes the warning reported from sparse:

  eeh-powernv.c:875:23: warning: constant 0x8000000000000000 is so big it is unsigned long

Fixes: ebe225312739 ("powerpc/powernv: Support PCI slot ID")
Suggested-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Gavin Shan <gwshan@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
diff --git a/arch/powerpc/include/asm/pnv-pci.h b/arch/powerpc/include/asm/pnv-pci.h
index 17e89dd..74b0b1e 100644
--- a/arch/powerpc/include/asm/pnv-pci.h
+++ b/arch/powerpc/include/asm/pnv-pci.h
@@ -15,7 +15,7 @@
 #include <misc/cxl-base.h>
 #include <asm/opal-api.h>
 
-#define PCI_SLOT_ID_PREFIX	0x8000000000000000
+#define PCI_SLOT_ID_PREFIX	(1UL << 63)
 #define PCI_SLOT_ID(phb_id, bdfn)	\
 	(PCI_SLOT_ID_PREFIX | ((uint64_t)(bdfn) << 16) | (phb_id))