resource: add resource_type() and IORESOURCE_TYPE_BITS

Add resource_type() and IORESOURCE_TYPE_BITS.  They make it easier to add
more resource types without having to rewrite tons of code.

Signed-off-by: Magnus Damm <damm@igel.co.jp>
Cc: Ben Dooks <ben-linux@fluff.org>
Cc: Jean Delvare <khali@linux-fr.org>
Cc: Paul Mundt <lethal@linux-sh.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>