wifi: ath10k: fix Wvoid-pointer-to-enum-cast warning

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

  ath10k/ahb.c:736:11: error: cast to smaller integer type 'enum ath10k_hw_rev' from 'const void *' [-Werror,-Wvoid-pointer-to-enum-cast]

Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Acked-by: Jeff Johnson <quic_jjohnson@quicinc.com>
Signed-off-by: Kalle Valo <quic_kvalo@quicinc.com>
Link: https://lore.kernel.org/r/20230810091224.70088-2-krzysztof.kozlowski@linaro.org