force st to use epoll

@@ -211,7 +211,7 @@ if [ $SRS_ARM_UBUNTU12 = YES ]; then
             rm -rf ${SRS_OBJS}/st-1.9 && cd ${SRS_OBJS} && 
             unzip -q ../3rdparty/st-1.9.zip && cd st-1.9 && 
             patch -p0 < ../../3rdparty/patches/1.st.arm.patch &&
-            make CC=${SrsArmCC} AR=${SrsArmAR} LD=${SrsArmLD} RANDLIB=${SrsArmRANDLIB} linux-debug &&
+            make CC=${SrsArmCC} AR=${SrsArmAR} LD=${SrsArmLD} RANDLIB=${SrsArmRANDLIB} EXTRA_CFLAGS="-DMD_HAVE_EPOLL" linux-debug &&
             cd .. && rm -rf st && ln -sf st-1.9/obj st &&
             cd .. && touch ${SRS_OBJS}/_flag.st.arm.tmp
         )
@@ -228,7 +228,7 @@ else
             echo "we alaways patch the st, for we may build srs under arm directly" &&
             echo "the 1.st.arm.patch is ok for x86 because it's only modify code under macro linux arm" &&
             patch -p0 < ../../3rdparty/patches/1.st.arm.patch &&
-            make linux-debug &&
+            make EXTRA_CFLAGS="-DMD_HAVE_EPOLL" linux-debug &&
             cd .. && rm -rf st && ln -sf st-1.9/obj st &&
             cd .. && rm -f ${SRS_OBJS}/_flag.st.arm.tmp
         )