Otherwise more complicated uart configuration won't be possible.
We can use r1 for tmp register for both head.S and debug.S.

NOTE: This patch depends on another patch to add the the tmp register
into all debug-macro.S files. That can be done with:

$ sed -i -e "s/addruart,rx|addruart, rx/addruart, rx, tmp/"
	arch/arm/*/include/*/debug-macro.S
Signed-off-by: NTony Lindgren <tony@atomide.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>