The CLKO2 clock source select list is the following as per the i.MX8M
Reference Manual:

000 - 25M_REF_CLK
001 - SYSTEM_PLL2_DIV5
010 - SYSTEM_PLL1_DIV2
011 - SYSTEM_PLL2_DIV6
100 - SYSTEM_PLL3_CLK
101 - AUDIO_PLL1_CLK
110 - VIDEO_PLL1_CLK
111 - 32K_REF_CLK

However, in imx8mq_clko2_sels[] only the first four entries are correct.

Fix it by adding the missing "sys3_pll2_out" entry in order to match
the description from the manual.

Fixes: b8052204 ("clk: imx: Add clock driver for i.MX8MQ CCM")
Reported-by: Rogerio Pimentel <rogerio.silva@nxp.com>
Signed-off-by: Fabio Estevam <festevam@gmail.com>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>