clk: sprd: set max_register according to mapping range

clk: sprd: set max_register according to mapping range

In sprd clock driver, regmap_config.max_register was set to a fixed value
which is likely larger than the address range configured in device tree,
when reading registers through debugfs it would cause access violation.

Fixes: d41f59fd92f2 ("clk: sprd: Add common infrastructure")
Signed-off-by: Chunyan Zhang <chunyan.zhang@unisoc.com>
Link: https://lore.kernel.org/r/20230316023624.758204-1-chunyan.zhang@unisoc.com
Signed-off-by: Stephen Boyd <sboyd@kernel.org>