clk: use clk_core_get_rate_recalc() in clk_rate_get()

In case clock flags contains CLK_GET_RATE_NOCACHE the clk_rate_get()
will return the cached rate. Thus, use clk_core_get_rate_recalc() which
takes proper action when clock flags contains CLK_GET_RATE_NOCACHE.

Signed-off-by: Claudiu Beznea <claudiu.beznea@microchip.com>
Link: https://lore.kernel.org/r/20211011112719.3951784-16-claudiu.beznea@microchip.com
Acked-by: Nicolas Ferre <nicolas.ferre@microchip.com>
[sboyd@kernel.org: Grab prepare lock around operation]
Signed-off-by: Stephen Boyd <sboyd@kernel.org>