Implement %pR to print struct resource content

Add a %pR option to the kernel vsnprintf that prints the range of
addresses inside a struct resource passed by pointer.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>