clk: qcom: branch: Add clk_branch2_prepare_ops

Add the clk_branch2_prepare_ops for supporting clock controller
where the hardware register is accessed by MDIO bus, and the
spin lock can't be used because of sleep during the MDIO
operation.

The clock is enabled by the .prepare instead of .enable when
the clk_branch2_prepare_ops is used.

Acked-by: Stephen Boyd <[e-mail]>
Signed-off-by: Luo Jie <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Bjorn Andersson <[e-mail]>

drivers/clk/qcom/clk-branch.c

···
 	.is_enabled = clk_is_enabled_regmap,
 };
 EXPORT_SYMBOL_GPL(clk_branch_simple_ops);
+
+const struct clk_ops clk_branch2_prepare_ops = {
+	.prepare = clk_branch2_enable,
+	.unprepare = clk_branch2_disable,
+	.is_prepared = clk_is_enabled_regmap,
+};
+EXPORT_SYMBOL_GPL(clk_branch2_prepare_ops);

drivers/clk/qcom/clk-branch.h

···
 extern const struct clk_ops clk_branch_simple_ops;
 extern const struct clk_ops clk_branch2_aon_ops;
 extern const struct clk_ops clk_branch2_mem_ops;
+extern const struct clk_ops clk_branch2_prepare_ops;
 
 #define to_clk_branch(_hw) \
 	container_of(to_clk_regmap(_hw), struct clk_branch, clkr)