clk: ti: Remove CLK_IS_BASIC check

This code is never called with a basic clock type, so the check
here is not doing anything useful and is blocking the removal of
__clk_get_flags(). Remove the check so we can delete the
__clk_get_flags() API.

Acked-by: Tero Kristo <t-kristo@ti.com>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>