clk: imx7ulp: Correct system clock source option #7

In the latest reference manual Rev.0,06/2019, the SCS's option #7
is no longer from upll, it is reserved, update clock driver accordingly.

Fixes: b1260067 ("clk: imx: add imx7ulp clk driver")
Signed-off-by: Anson Huang <Anson.Huang@nxp.com>
Reviewed-by: Fabio Estevam <festevam@gmail.com>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>

drivers/clk/imx/clk-imx7ulp.c

@@ -24,7 +24,7 @@ static const char * const spll_pfd_sels[]	= { "spll_pfd0", "spll_pfd1", "spll_pf
 static const char * const spll_sels[]		= { "spll", "spll_pfd_sel", };
 static const char * const apll_pfd_sels[]	= { "apll_pfd0", "apll_pfd1", "apll_pfd2", "apll_pfd3", };
 static const char * const apll_sels[]		= { "apll", "apll_pfd_sel", };
-static const char * const scs_sels[]		= { "dummy", "sosc", "sirc", "firc", "dummy", "apll_sel", "spll_sel", "upll", };
+static const char * const scs_sels[]		= { "dummy", "sosc", "sirc", "firc", "dummy", "apll_sel", "spll_sel", "dummy", };
 static const char * const ddr_sels[]		= { "apll_pfd_sel", "upll", };
 static const char * const nic_sels[]		= { "firc", "ddr_clk", };
 static const char * const periph_plat_sels[]	= { "dummy", "nic1_bus_clk", "nic1_clk", "ddr_clk", "apll_pfd2", "apll_pfd1", "apll_pfd0", "upll", };