mrw-rev.bbclass: bump version

Change-Id: I27c40ed4c0581680bb4541d80d90c1385398801f
Signed-off-by: Patrick Williams <patrick@stwcx.xyz>
diff --git a/classes/mrw-rev.bbclass b/classes/mrw-rev.bbclass
index 2998314..88dbf64 100644
--- a/classes/mrw-rev.bbclass
+++ b/classes/mrw-rev.bbclass
@@ -2,4 +2,4 @@
 MRW_API_SRCREV ?= "04f15f37e9ab6c09412a0abcffb87e9aefcc5368"
 
 MRW_PATCH_SRC_URI ?= "git://github.com/openbmc/phosphor-mrw-tools"
-MRW_PATCH_SRCREV ?= "7a68567af7bf121143ef135152a39723518b6e06"
+MRW_PATCH_SRCREV ?= "cb99d1ea2c77c704e7991733fa36848e211567af"