staging/rtl8187se: Mark functions as static to silence sparse

Sparse complains that some functions can be declared as static:
123:6: warning: symbol 'PlatformIOWrite1Byte' was not declared. Should it be static?
129:6: warning: symbol 'PlatformIOWrite2Byte' was not declared. Should it be static?
135:6: warning: symbol 'PlatformIOWrite4Byte' was not declared. Should it be static?
178:6: warning: symbol 'SetOutputEnableOfRfPins' was not declared.  Should it be static?
354:6: warning: symbol 'ZEBRA_Config_85BASIC_HardCode' was not declared.  Should it be static?
655:6: warning: symbol 'InitTxPwrTracking87SE' was not declared. Should it be static?
665:6: warning: symbol 'PhyConfig8185' was not declared. Should it be static?
692:6: warning: symbol 'HwConfigureRTL8185' was not declared. Should it be static?
817:4: warning: symbol 'GetSupportedWirelessMode8185' was not declared.  Should it be static?
822:6: warning: symbol 'ActUpdateChannelAccessSetting' was not declared.  Should it be static?
857:6: warning: symbol 'ActSetWirelessMode8185' was not declared. Should it be static?
914:6: warning: symbol 'MgntDisconnectIBSS' was not declared. Should it be static?
940:6: warning: symbol 'MlmeDisassociateRequest' was not declared.  Should it be static?
957:6: warning: symbol 'MgntDisconnectAP' was not declared. Should it be static?
975:6: warning: symbol 'MgntDisconnect' was not declared. Should it be static?
1011:6: warning: symbol 'SetRFPowerState' was not declared. Should it be static?
1115:6: warning: symbol 'InactivePowerSave' was not declared. Should it be static?

-> Add the static keyword.

Signed-off-by: Peter Huewe <peterhuewe@gmx.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>