clk: visconti: prevent array overflow in visconti_clk_register_gates()

This code was using -1 to represent that there was no reset function.
Unfortunately, the -1 was stored in u8 so the if (clks[i].rs_id >= 0)
condition was always true. This lead to an out of bounds access in
visconti_clk_register_gates().

Fixes: b4cbe606dc36 ("clk: visconti: Add support common clock driver and reset driver")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Link: https://lore.kernel.org/r/20220316083533.GA30941@kili
Acked-by: Nobuhiro Iwamatsu <nobuhiro1.iwamatsu@toshiba.co.jp>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>

clk: visconti: Add support common clock driver and reset driver

Add support for common interface of the common clock and reset driver
for Toshiba Visconti5 and its SoC, TMPV7708. The PIPLLCT provides the PLL,
and the PISMU provides clock and reset functionality.
Each drivers are provided in this patch.

Signed-off-by: Nobuhiro Iwamatsu <nobuhiro1.iwamatsu@toshiba.co.jp>
Link: https://lore.kernel.org/r/20211025031038.4180686-4-nobuhiro1.iwamatsu@toshiba.co.jp
[sboyd@kernel.org: Add bitfield.h include to pll.c]
Signed-off-by: Stephen Boyd <sboyd@kernel.org>