ARM: removing support for etb/etm in "arch/arm/kernel/"

Removing minimal support for etb/etm to favour an implementation
that is more flexible, extensible and capable of handling more
platforms.

Also removing the only client of the old driver.  That code can
easily be replaced by entries for etb/etm in the device tree.

Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
(cherry picked from commit 184901a06a366d40386e07307bcadc9eeaabbd39)
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>

Conflicts:
	arch/arm/include/asm/hardware/coresight.h
	arch/arm/kernel/Makefile
	arch/arm/kernel/etm.c
	arch/arm/mach-omap2/Kconfig