lib: consolidate hang()

Delete all occurrences of hang() and provide a generic function.

Signed-off-by: Andreas Bießmann <andreas.devel@googlemail.com>
Acked-by: Albert ARIBAUD <albert.u.boot@aribaud.net>
[trini: Modify check around puts() in hang.c slightly]
Signed-off-by: Tom Rini <trini@ti.com>

lib/Makefile

@@ -71,6 +71,7 @@ COBJS-$(CONFIG_BCH) += bch.o
 COBJS-y += crc32.o
 COBJS-y += ctype.o
 COBJS-y += div64.o
+COBJS-y += hang.o
 COBJS-y += linux_string.o
 COBJS-$(CONFIG_REGEX) += slre.o
 COBJS-y += string.o