clk: en7523: fix rate divider for slic and spi clocks

Introduce div_offset field in en_clk_desc struct in order to fix rate
divider estimation in en7523_get_div routine for slic and spi fixed
rate clocks.
Moreover, fix base_shift for crypto clock.

Fixes: 1e627317 ("clk: en7523: Add clock driver for Airoha EN7523 SoC")
Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
Link: https://lore.kernel.org/r/c491bdea05d847f1f1294b94f14725d292eb95d0.1718615934.git.lorenzo@kernel.org


Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>