[MIPS] Remove unused pnx8550 Kconfig

Signed-off-by: NYoichi Yuasa <yoichi_yuasa@tripeaks.co.jp>
Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

arch/mips/Kconfig

@@ -604,7 +604,6 @@ source "arch/mips/sibyte/Kconfig"
 source "arch/mips/tx4927/Kconfig"
 source "arch/mips/tx4938/Kconfig"
 source "arch/mips/vr41xx/Kconfig"
-source "arch/mips/philips/pnx8550/common/Kconfig"
 
 endmenu
 

arch/mips/philips/pnx8550/common/Kconfig

-# Place holder