mb/prodrive/atlas: Configure eSPI IO decode ranges for EC

This implementation adds eSPI IO decode range for EC.
1. 0x800-0x8FF / 0x200-020F: EC host command range.
2. 0x900-0x9ff: EC memory map range.

Signed-off-by: Lean Sheng Tan <sheng.tan@9elements.com>
Change-Id: I787561287025e33a8622eb9b3565fa14d0416c46
Reviewed-on: https://review.coreboot.org/c/coreboot/+/63465
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Angel Pons <th3fanbus@gmail.com>
diff --git a/src/mainboard/prodrive/atlas/devicetree.cb b/src/mainboard/prodrive/atlas/devicetree.cb
index 1a3a058..63c34ad 100644
--- a/src/mainboard/prodrive/atlas/devicetree.cb
+++ b/src/mainboard/prodrive/atlas/devicetree.cb
@@ -8,6 +8,12 @@
 	register "pmc_gpe0_dw1" = "GPP_D"
 	register "pmc_gpe0_dw2" = "GPP_E"
 
+	# EC host command ranges are in 0x800-0x8ff & 0x200-0x20f
+	register "gen1_dec" = "0x00fc0801"
+	register "gen2_dec" = "0x000c0201"
+	# EC memory map range is 0x900-0x9ff
+	register "gen3_dec" = "0x00fc0901"
+
 	# USB configuration
 	register "usb2_ports[0]" = "USB2_PORT_MID(OC0)"
 	register "usb2_ports[1]" = "USB2_PORT_MID(OC0)"