ath11k: Remove unnecessary enum scan_priority

Clang warns:

drivers/net/wireless/ath/ath11k/wmi.c:1827:23: warning: implicit
conversion from enumeration type 'enum wmi_scan_priority' to different
enumeration type 'enum scan_priority' [-Wenum-conversion]
        arg->scan_priority = WMI_SCAN_PRIORITY_LOW;
                           ~ ^~~~~~~~~~~~~~~~~~~~~
1 warning generated.

wmi_scan_priority and scan_priority have the same values but the wmi one
has WMI prefixed to the names. Since that enum is already being used,
get rid of scan_priority and switch its one use to wmi_scan_priority to
fix this warning.

Fixes: d5c65159 ("ath11k: driver for Qualcomm IEEE 802.11ax devices")
Link: https://github.com/ClangBuiltLinux/linux/issues/808


Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>