sh: remove old TMU driver

This patch removes the old TMU driver (CONFIG_SH_TMU/timer-tmu.c)

As replacement, select the sh_tmu driver with CONFIG_SH_TIMER_TMU
and configure timer channel using platform data.

If multiple TMU channels are enabled using platform data, use the
earlytimer parameter on the kernel command line to select channel.
For instance, use "earlytimer=sh_tmu.0" to select the first channel.

To verify which timer is being used, look at printouts or the timer
irq count in /proc/interrupts.

Signed-off-by: Magnus Damm <damm@igel.co.jp>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>