soc/intel/common/block: Add HECI driver

Add common driver that can send/receive HECI messages. This driver is
inspired by Linux kernel mei driver and somewhat based on Skylake's.
Currently it has been only tested on Apollolake.

BUG=b:35586975
BRANCH=reef
TEST=tested on Apollolake to send single messages and receive both
fragmented and non-fragmented versions.

Change-Id: Ie3772700270f4f333292b80d59f79555851780f7
Signed-off-by: Andrey Petrov <andrey.petrov@intel.com>
Reviewed-on: https://review.coreboot.org/18547
Reviewed-by: Aaron Durbin <adurbin@chromium.org>
Tested-by: build bot (Jenkins)
diff --git a/src/soc/intel/common/block/cse/Kconfig b/src/soc/intel/common/block/cse/Kconfig
new file mode 100644
index 0000000..441ff93
--- /dev/null
+++ b/src/soc/intel/common/block/cse/Kconfig
@@ -0,0 +1,7 @@
+config SOC_INTEL_COMMON_BLOCK_CSE
+	bool
+	default n
+	help
+	  Driver for communication with Converged Security Engine (CSE)
+	  over Host Embedded Controller Interface (HECI)
+