leds: pca955x: Fix -Wvoid-pointer-to-enum-cast warning

When building with clang 18 I see the following warning:
| drivers/leds/leds-pca955x.c:487:15: warning: cast to smaller integer
| type 'enum pca955x_type' from 'const void *' [-Wvoid-pointer-to-enum-cast]
| 487 | chip_type = (enum pca955x_type)md;

This is due to the fact that `md` is a void* while `enum pca995x_type` has the
size of an int.

Add uintptr_t cast to silence clang warning while also keeping enum cast
for readability and consistency with other `chip_type` assignment just a
few lines below:
| chip_type = (enum pca955x_type)id->driver_data;

Reported-by: Nathan Chancellor <[e-mail]>
Closes: https://github.com/ClangBuiltLinux/linux/issues/1910
Signed-off-by: Justin Stitt <[e-mail]>
Reviewed-by: Nathan Chancellor <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Lee Jones <[e-mail]>

drivers/leds/leds-pca955x.c

···
 	const void *md = device_get_match_data(&client->dev);
 
 	if (md) {
-		chip_type = (enum pca955x_type)md;
+		chip_type = (enum pca955x_type)(uintptr_t)md;
 	} else {
 		const struct i2c_device_id *id = i2c_match_id(pca955x_id,
 							      client);