mfd: hi6421-pmic: Fix Wvoid-pointer-to-enum-cast warning

'type' is an enum, thus cast of pointer on 64-bit compile test with W=1
causes:

  hi6421-pmic-core.c:62:9: error: cast to smaller integer type 'enum hi6421_type' from 'const void *' [-Werror,-Wvoid-pointer-to-enum-cast]

Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Link: https://lore.kernel.org/r/20230810095849.123321-4-krzysztof.kozlowski@linaro.org


Signed-off-by: Lee Jones <lee@kernel.org>