clk: ti: Fix some errors found by static checkers

drivers/clk/ti/clk-814x.c:34:12: warning: symbol 'dm814x_adpll_early_init' was not declared. Should it be static?
drivers/clk/ti/clk-814x.c:58:12: warning: symbol 'dm814x_adpll_enable_init_clocks' was not declared. Should it be static?
drivers/clk/ti/adpll.c:465 ti_adpll_recalc_rate() warn: should '__readw(d->regs + 20) << 18' be a 64 bit type?
drivers/clk/ti/adpll.c:945 ti_adpll_probe() error: we previously assumed 'd->clocks' could be null (see line 921)

The last one looks like a real bug because we don't return an
error on allocation failure.

Cc: Tero Kristo <t-kristo@ti.com>
Tested-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>