asm-generic/io.h: move ioremap_nocache/ioremap_uc/ioremap_wc/ioremap_wt out of ifndef CONFIG_MMU

It allows some architectures to use this generic macro instead of
defining theirs.

sparc: io: To use the define of ioremap_[nocache|wc|wb] in asm-generic/io.h
It will move the ioremap_nocache out of the CONFIG_MMU ifdef. This means that
in order to suppress re-definition errors we need to remove the #define
in arch/sparc/include/asm/io_32.h. Also, the change adds a prototype for
ioremap where size is size_t and offset is phys_addr_t so fix that as well.

Signed-off-by: Greentime Hu <greentime@andestech.com>

arch/sparc/include/asm/io_32.h

@@ -127,12 +127,7 @@ static inline void sbus_memcpy_toio(volatile void __iomem *dst,
  * Bus number may be embedded in the higher bits of the physical address.
  * This is why we have no bus number argument to ioremap().
  */
-void __iomem *ioremap(unsigned long offset, unsigned long size);
-#define ioremap_nocache(X,Y)	ioremap((X),(Y))
-#define ioremap_wc(X,Y)		ioremap((X),(Y))
-#define ioremap_wt(X,Y)		ioremap((X),(Y))
 void iounmap(volatile void __iomem *addr);
-
 /* Create a virtual mapping cookie for an IO port range */
 void __iomem *ioport_map(unsigned long port, unsigned int nr);
 void ioport_unmap(void __iomem *);