csky: fixup abiv2 mmap(... O_SYNC) failed.

Glibc function mmap(... O_SYNC) will make page to _PAGE_UNCACHE +
_PAGE_SO and strong-order page couldn't support unalignment access.
So remove _PAGE_SO from _PAGE_UNCACHE, also sync abiv1 with the macro
of _PAGE_SO.
Signed-off-by: Guo Ren <ren_guo@c-sky.com>
Reported-by: Liu Renwei <Renwei.Liu@verisilicon.com>
Tested-by: Yuan Qiyun <qiyun_yuan@c-sky.com>

arch/csky/abiv1/inc/abi/pgtable-bits.h

@@ -26,6 +26,7 @@
 
 #define _PAGE_CACHE		(3<<9)
 #define _PAGE_UNCACHE		(2<<9)
+#define _PAGE_SO		_PAGE_UNCACHE
 
 #define _CACHE_MASK		(7<<9)
 

arch/csky/abiv2/inc/abi/pgtable-bits.h

@@ -32,6 +32,6 @@
 #define _CACHE_MASK		_PAGE_CACHE
 
 #define _CACHE_CACHED		(_PAGE_VALID | _PAGE_CACHE | _PAGE_BUF)
-#define _CACHE_UNCACHED		(_PAGE_VALID | _PAGE_SO)
+#define _CACHE_UNCACHED		(_PAGE_VALID)
 
 #endif /* __ASM_CSKY_PGTABLE_BITS_H */

arch/csky/mm/ioremap.c

@@ -30,7 +30,7 @@ void __iomem *ioremap(phys_addr_t addr, size_t size)
 	vaddr = (unsigned long)area->addr;
 
 	prot = __pgprot(_PAGE_PRESENT | __READABLE | __WRITEABLE |
-			_PAGE_GLOBAL | _CACHE_UNCACHED);
+			_PAGE_GLOBAL | _CACHE_UNCACHED | _PAGE_SO);
 
 	if (ioremap_page_range(vaddr, vaddr + size, addr, prot)) {
 		free_vm_area(area);