markw: ril: Fix the rild.libargs space breakage

* Due to PRODUCT_PROPERTY_OVERRIDES parsing with spaces,
    the rild.libargs property got broken in 2 parts,
    which basically breaks second SIM support on Z3+/Z5 Dual.

 * Use the regex symbol "[SPACE]" to handle this needed space

Change-Id: I9a00d4bce099a0513b5b3070c843efa7c2faf697

prop.mk

@@ -177,7 +177,7 @@ persist.vendor.radio.custom_ecc=1 \
 persist.vendor.radio.rat_on=combine \
 persist.vendor.radio.sib16_support=1 \
 ril.subscription.types=NV,RUIM \
-rild.libargs=-d/dev/smd0 \
+rild.libargs=-d[SPACE]/dev/smd0 \
 rild.libpath=/vendor/lib64/libril-qc-qmi-1.so \
 ro.telephony.call_ring.multiple=false \
 ro.telephony.default_network=22,20 \