sh: Fix cached/uncaced address calculation in 29bit mode

In the case of 29bit mode, CAC/UNCAC_ADDR does not return a right address.
This revises this problem by using P1SEGADDR and P2SEGADDR in 29bit mode.

Reported-by: Yutaro Ebihara <ebiharaml@si-linux.co.jp>
Signed-off-by: Nobuhiro Iwamatsu <nobuhiro.iwamatsu.yj@renesas.com>
Tested-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Tested-by: Simon Horman <horms@verge.net.au>
Cc: stable@kernel.org
Signed-off-by: Paul Mundt <lethal@linux-sh.org>