Remove the mlx5 driver from LINT kernel config for 32-bit PPC

The mlx5 driver requires 64-bit atomics, which are not supported on 32-bit
PPC. Exclude that driver from the LINT kernel config.

Submitted by:	hps (but I re-worded the comment)
Reported by:	rpokala
Reviewed by:	jhibbits
Differential Revision:	https://reviews.freebsd.org/D15611

sys/conf/makeLINT.mk

@@ -55,4 +55,8 @@ LINT: ${NOTES} ${MAKELINT_SED}
 	cat ${.TARGET} > ${.TARGET}64
 	echo "machine	${TARGET} powerpc" >> ${.TARGET}
 	echo "machine	${TARGET} powerpc64" >> ${.TARGET}64
+# mlx5 needs 64-bit atomics, so exclude from 32-bit PPC
+	echo "nodevice mlx5" >> ${.TARGET}
+	echo "nodevice mlx5en" >> ${.TARGET}
+	echo "nodevice mlx5ib" >> ${.TARGET}
 .endif