irdma: normalize .CURDIR-relative paths to SRCTOP

Sponsored by:	Juniper Networks, Inc.
MFC after:	1 week
Reviewed by:	markj
Differential Revision:	https://reviews.freebsd.org/D52192

sys/modules/irdma/Makefile

@@ -1,8 +1,8 @@
 .include <bsd.own.mk>
 
-OFED_INC_DIR = ${.CURDIR}/../../ofed/include
-ICE_DIR = ${.CURDIR}/../../dev/ice
-.PATH:	${.CURDIR}/../../dev/irdma
+OFED_INC_DIR = ${SRCTOP}/sys/ofed/include
+ICE_DIR = ${SRCTOP}/sys/dev/ice
+.PATH:	${SRCTOP}/sys/dev/irdma
 
 KMOD=	irdma
 SRCS=	icrdma.c