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

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 <nathan@kernel.org>
Closes: https://github.com/ClangBuiltLinux/linux/issues/1910
Signed-off-by: Justin Stitt <justinstitt@google.com>
Reviewed-by: Nathan Chancellor <nathan@kernel.org>
Link: https://lore.kernel.org/r/20230816-void-drivers-leds-leds-pca955x-v1-1-2967e4c1bdcc@google.com
Signed-off-by: Lee Jones <lee@kernel.org>