net: sh-eth: Fix build error by the value which is not defined

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drivers/net/ethernet/renesas/sh_eth.c:1706: error: 'pdid' undeclared (first use in this function)
drivers/net/ethernet/renesas/sh_eth.c:1706: error: (Each undeclared identifier is reported only once
drivers/net/ethernet/renesas/sh_eth.c:1706: error: for each function it appears in.)
make[5]: *** [drivers/net/ethernet/renesas/sh_eth.o] Error 1
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Signed-off-by: Nobuhiro Iwamatsu <nobuhiro.iwamatsu.yj@renesas.com>
CC: Florian Fainelli <florian@openwrt.org>
Signed-off-by: David S. Miller <davem@davemloft.net>