mtd: rawnand: fsmc: Use helper function devm_clk_get_enabled()

mtd: rawnand: fsmc: Use helper function devm_clk_get_enabled()

Since commit 7ef9651e9792 ("clk: Provide new devm_clk helpers for prepared
and enabled clocks"), devm_clk_get() and clk_prepare_enable() can now be
replaced by devm_clk_get_enabled() when driver enables (and possibly
prepares) the clocks for the whole lifetime of the device. Moreover, it is
no longer necessary to unprepare and disable the clocks explicitly. The
label "disable_clk" no longer makes sense, rename it to "disable_fsmc".

Reviewed-by: Miquel Raynal <miquel.raynal@bootlin.com>
Signed-off-by: Li Zetao <lizetao1@huawei.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/20230821031737.1973183-4-lizetao1@huawei.com