Add support for Intel Silvermont: Bay Trail, Rangeley and Avoton

The core of this patch to support Bay Trail originally came from the
Chromiumos flashrom repo and was modified by Sage to support the
Rangeley/Avoton parts as well.
Because that was not complicated enough already Stefan Tauner refactored
and refined everything. Bay Trail seems to be the first Atom SoC able to
support hwseq. No SPI Programming Guide could be obtained so it is
handled similarly to Lynx Point which seems to be its nearest relative.

Corresponding to flashrom svn r1844.

Signed-off-by: Duncan Laurie <dlaurie@chromium.org>
Signed-off-by: Martin Roth <gaumless@gmail.com>
Signed-off-by: Stefan Tauner <stefan.tauner@alumni.tuwien.ac.at>
Tested-by: Marc Jones <marcj303@gmail.com>
Tested-by: Stefan Tauner <stefan.tauner@alumni.tuwien.ac.at>
Tested-by: Thomas Reardon <thomas_reardon@hotmail.com>
Tested-by: Wen Wang <wen.wang@adiengineering.com>
Acked-by: Marc Jones <marcj303@gmail.com>
Acked-by: Stefan Tauner <stefan.tauner@alumni.tuwien.ac.at>
diff --git a/ich_descriptors.c b/ich_descriptors.c
index b1e081f..90f3150 100644
--- a/ich_descriptors.c
+++ b/ich_descriptors.c
@@ -139,6 +139,7 @@
 		return size_str[size_enc];
 	}
 	case CHIPSET_8_SERIES_LYNX_POINT:
+	case CHIPSET_BAYTRAIL:
 	case CHIPSET_8_SERIES_LYNX_POINT_LP:
 	case CHIPSET_8_SERIES_WELLSBURG: {
 		uint8_t size_enc;
@@ -180,6 +181,7 @@
 	case CHIPSET_6_SERIES_COUGAR_POINT:
 	case CHIPSET_7_SERIES_PANTHER_POINT:
 	case CHIPSET_8_SERIES_LYNX_POINT:
+	case CHIPSET_BAYTRAIL:
 	case CHIPSET_8_SERIES_LYNX_POINT_LP:
 	case CHIPSET_8_SERIES_WELLSBURG:
 		return freq_str[value];
@@ -820,6 +822,7 @@
 		size_max = 5;
 		break;
 	case CHIPSET_8_SERIES_LYNX_POINT:
+	case CHIPSET_BAYTRAIL:
 	case CHIPSET_8_SERIES_LYNX_POINT_LP:
 	case CHIPSET_8_SERIES_WELLSBURG:
 		if (idx == 0) {