sh: Use clk_always_enable() on sh7343 / SE77343

Use clk_always_enable() on the sh7343 processor and in the board code
for Solution Engine 7343. Remove duplicate MSTPCR register definitions.

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