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/kernel/ioport.c

@@ -122,12 +122,12 @@ static void xres_free(struct xresource *xrp) {
  *
  * Bus type is always zero on IIep.
  */
-void __iomem *ioremap(unsigned long offset, unsigned long size)
+void __iomem *ioremap(phys_addr_t offset, size_t size)
 {
 	char name[14];
 
 	sprintf(name, "phys_%08x", (u32)offset);
-	return _sparc_alloc_io(0, offset, size, name);
+	return _sparc_alloc_io(0, (unsigned long)offset, size, name);
 }
 EXPORT_SYMBOL(ioremap);