pmacAsynIPPortSrc does not build on windows-x64

[MarkRivers]

The following change is required to build pmacAsynIPPortSrc on windows-x64, i.e. to build the dll.

diff --git a/pmacApp/pmacAsynIPPortSrc/Makefile b/pmacApp/pmacAsynIPPortSrc/Makefile
index 9312f83..55e5874 100644
--- a/pmacApp/pmacAsynIPPortSrc/Makefile
+++ b/pmacApp/pmacAsynIPPortSrc/Makefile
@@ -10,4 +10,8 @@ INC += pmacAsynIPPort.h
 LIBRARY = pmacAsynIPPort
 pmacAsynIPPort_SRCS = pmacAsynIPPort.c

+pmacAsynIPPort_LIBS += asyn
+pmacAsynIPPort_LIBS += $(EPICS_BASE_IOC_LIBS)
+pmacAsynIPPort_SYS_LIBS_WIN32 += ws2_32
+
 include $(TOP)/configure/RULES