sh: boards: convert to SPDX identifiers

Update license to use SPDX-License-Identifier instead of verbose license
text.

Link: http://lkml.kernel.org/r/87in08ct0n.wl-kuninori.morimoto.gx@renesas.com
Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Reviewed-by: Simon Horman <horms+renesas@verge.net.au>
Cc: Rich Felker <dalias@libc.org>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

sh: shared register saving code for sh3/sh4/sh4a

This patch reworks the sh3/sh4/sh4a register saving code in
the following ways:
- break out prepare_stack_save_dsp() from handle_exception()
- break out save_regs() from handle_exception()
- the register saving order is unchanged
- align new functions to fit in cache lines
- separate exception code from interrupt code
- keep main code flow in a single cache line per exception vector
- use bsr/rts for regular functions (save pr first)
- keep data in one shared cache line (exception_data)
- document the functions
- tie in the hp6xx code

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

sh: Shuffle the board directories in to mach groups.

This flattens out the board directories in to individual mach groups,
we will use this for getting rid of unneeded directories, simplifying
the build system, and becoming more coherent with the refactored
arch/sh/include topology.

Signed-off-by: Paul Mundt <lethal@linux-sh.org>