riscv: Cleanup unused functions

These functions haven't been used, so just remove them. The patch
has been tested with riscv.

Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Anup Patel <anup@brainfault.org>
Reviewed-by: Palmer Dabbelt <palmerdabbelt@google.com>
Acked-by: Palmer Dabbelt <palmerdabbelt@google.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>

Author: guoren83

arch/riscv/include/asm/page.h

@@ -37,16 +37,6 @@
 
 #ifndef __ASSEMBLY__
 
-#define PAGE_UP(addr)	(((addr)+((PAGE_SIZE)-1))&(~((PAGE_SIZE)-1)))
-#define PAGE_DOWN(addr)	((addr)&(~((PAGE_SIZE)-1)))
-
-/* align addr on a size boundary - adjust address up/down if needed */
-#define _ALIGN_UP(addr, size)	(((addr)+((size)-1))&(~((size)-1)))
-#define _ALIGN_DOWN(addr, size)	((addr)&(~((size)-1)))
-
-/* align addr on a size boundary - adjust address up if needed */
-#define _ALIGN(addr, size)	_ALIGN_UP(addr, size)
-
 #define clear_page(pgaddr)			memset((pgaddr), 0, PAGE_SIZE)
 #define copy_page(to, from)			memcpy((to), (from), PAGE_SIZE)