soc: sifive: ccache: fix missing iounmap() in error path in sifive_ccache_init()

soc: sifive: ccache: fix missing iounmap() in error path in sifive_ccache_init()

[ Upstream commit 73e770f085023da327dc9ffeb6cd96b0bb22d97e ]

Add missing iounmap() before return error from sifive_ccache_init().

Fixes: a967a289f169 ("RISC-V: sifive_l2_cache: Add L2 cache controller driver for SiFive SoCs")
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
Signed-off-by: Conor Dooley <conor.dooley@microchip.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>