rtlwifi: rtl8192de: Fix build errors when using allyes configuration

After adding rtl8192de to linux-next, making the rtlwifi drivers be built-in
results in the following warnings:

  LD      drivers/net/wireless/rtlwifi/built-in.o
drivers/net/wireless/rtlwifi/rtl8192de/built-in.o: In function `rtl92ce_sw_led_on':
(.text+0x11fb6): multiple definition of `rtl92ce_sw_led_on'
drivers/net/wireless/rtlwifi/rtl8192ce/built-in.o:(.text+0xa326): first defined here
drivers/net/wireless/rtlwifi/rtl8192de/built-in.o:(.bss+0x0): multiple definition of `dm_digtable'
drivers/net/wireless/rtlwifi/rtl8192c/built-in.o:(.bss+0x0): first defined here
ld: Warning: size of symbol `dm_digtable' changed from 40 in drivers/net/wireless/rtlwifi/rtl8192c/built-in.o to 48 in drivers/net/wireless/rtlwifi/rtl8192de/built-in.o
drivers/net/wireless/rtlwifi/rtl8192de/built-in.o: In function `rtl92ce_sw_led_off':
(.text+0x11cfe): multiple definition of `rtl92ce_sw_led_off'
drivers/net/wireless/rtlwifi/rtl8192ce/built-in.o:(.text+0xa06e): first defined here

Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Larry Finger <Larry.Finger@lwfinger.net>
Acked-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: John W. Linville <linville@tuxdriver.com>