staging: rtl8192u: Added in r819xU_firmware_img.c an include to fix a sparse warning

Fix the following warnings from sparse in r819xU_firmware_img.c
due to the missing include of r819xU_firmware_img.h

  CHECK   drivers/staging/rtl8192u/r819xU_firmware_img.c
drivers/staging/rtl8192u/r819xU_firmware_img.c:4:5: warning: symbol 'Rtl8192UsbPHY_REGArray' was not declared. Should it be static?
drivers/staging/rtl8192u/r819xU_firmware_img.c:7:5: warning: symbol 'Rtl8192UsbPHY_REG_1T2RArray' was not declared. Should it be static?
drivers/staging/rtl8192u/r819xU_firmware_img.c:158:5: warning: symbol 'Rtl8192UsbRadioA_Array' was not declared. Should it be static?
drivers/staging/rtl8192u/r819xU_firmware_img.c:284:5: warning: symbol 'Rtl8192UsbRadioB_Array' was not declared. Should it be static?
drivers/staging/rtl8192u/r819xU_firmware_img.c:326:5: warning: symbol 'Rtl8192UsbRadioC_Array' was not declared. Should it be static?
drivers/staging/rtl8192u/r819xU_firmware_img.c:329:5: warning: symbol 'Rtl8192UsbRadioD_Array' was not declared. Should it be static?
drivers/staging/rtl8192u/r819xU_firmware_img.c:332:5: warning: symbol 'Rtl8192UsbMACPHY_Array' was not declared. Should it be static?
drivers/staging/rtl8192u/r819xU_firmware_img.c:341:5: warning: symbol 'Rtl8192UsbMACPHY_Array_PG' was not declared. Should it be static?
drivers/staging/rtl8192u/r819xU_firmware_img.c:354:5: warning: symbol 'Rtl8192UsbAGCTAB_Array' was not declared. Should it be static?

Signed-off-by: Ana Rey <anarey@gmail.com>
Signed-off-by: Peter P Waskiewicz Jr <peter.p.waskiewicz.jr@intel.com>