staging: rtlwifi: Use proper enumerated types for Wi-Fi only interface

staging: rtlwifi: Use proper enumerated types for Wi-Fi only interface

Clang warns when one enumerated type is implicitly converted to another.

drivers/staging/rtlwifi/btcoexist/halbtcoutsrc.c:1264:34: warning:
implicit conversion from enumeration type 'enum btc_chip_interface' to
different enumeration type 'enum wifionly_chip_interface'
[-Wenum-conversion]
                wifionly_cfg->chip_interface = BTC_INTF_PCI;
                                             ~ ^~~~~~~~~~~~
drivers/staging/rtlwifi/btcoexist/halbtcoutsrc.c:1267:34: warning:
implicit conversion from enumeration type 'enum btc_chip_interface' to
different enumeration type 'enum wifionly_chip_interface'
[-Wenum-conversion]
                wifionly_cfg->chip_interface = BTC_INTF_USB;
                                             ~ ^~~~~~~~~~~~
drivers/staging/rtlwifi/btcoexist/halbtcoutsrc.c:1270:34: warning:
implicit conversion from enumeration type 'enum btc_chip_interface' to
different enumeration type 'enum wifionly_chip_interface'
[-Wenum-conversion]
                wifionly_cfg->chip_interface = BTC_INTF_UNKNOWN;
                                             ~ ^~~~~~~~~~~~~~~~
3 warnings generated.

Use the values from the correct enumerated type, wifionly_chip_interface.

BTC_INTF_UNKNOWN = WIFIONLY_INTF_UNKNOWN = 0
BTC_INTF_PCI = WIFIONLY_INTF_PCI = 1
BTC_INTF_USB = WIFIONLY_INTF_USB = 2

Link: https://github.com/ClangBuiltLinux/linux/issues/171
Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>