ANDROID: GKI: fix up crc change in ip.h

Commit 92071a2b ("net: lwtunnel: handle MTU calculation in
forwading") was backported to 5.4.132 and it caused a crc change in
include/net/ip.h due to a new .h file being included.

No real abi change happened here, so just #ifdef the .h file out when
doing the crc check.

Bug: 161946584
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
Change-Id: I1bad0458bc0f9130239fc94ca982e800681cd443