clk: mediatek: Export required common code symbols

To make clk-mt8365 compilable as a module there are a few function
symbols missing. This patch adds the required EXPORT_SYMBOL_GPL to the
functions.

Signed-off-by: Markus Schneider-Pargmann <msp@baylibre.com>
Link: https://lore.kernel.org/r/20220822152652.3499972-4-msp@baylibre.com


Signed-off-by: Stephen Boyd <sboyd@kernel.org>