clk: qoriq: avoid format string warning

clang-22 warns about the use of non-variadic format arguments passed into
snprintf():

drivers/clk/clk-qoriq.c:925:39: error: diagnostic behavior may be improved by adding the
'format(printf, 7, 8)' attribute to the declaration of 'create_mux_common' [-Werror,-Wmissing-format-attribute]
910 | static struct clk * __init create_mux_common(struct clockgen *cg,
| __attribute__((format(printf, 7, 8)))
911 | struct mux_hwclock *hwc,
912 | const struct clk_ops *ops,
913 | unsigned long min_rate,
914 | unsigned long max_rate,
915 | unsigned long pct80_rate,
916 | const char *fmt, int idx)
917 | {
918 | struct clk_init_data init = {};
919 | struct clk *clk;
920 | const struct clockgen_pll_div *div;
921 | const char *parent_names[NUM_MUX_PARENTS];
922 | char name[32];
923 | int i, j;
924 |
925 | snprintf(name, sizeof(name), fmt, idx);
| ^
drivers/clk/clk-qoriq.c:910:28: note: 'create_mux_common' declared here
910 | static struct clk * __init create_mux_common(struct clockgen *cg,

Rework this to pass the 'int idx' as a varargs argument, allowing the
format string to be verified at the caller location.

Fixes: 0dfc86b3173f ("clk: qoriq: Move chip-specific knowledge into driver")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Kees Cook <kees@kernel.org>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>