RPi3: expose SDHost controller in DSDT

Expose both SD controllers to HLOS. UEFI can
use either to route uSD slot to.

This merges #33

Signed-off-by: Andrei Warkentin <andrey.warkentin@gmail.com>

AcpiTables/Sdhc.asl

@@ -1,7 +1,7 @@
 /*
  * [DSDT] SD controller/card definition.
  *
- * UEFI uses Arasan today, so that's all we expose.
+ * UEFI can use either SDHost or Arasan. We expose both to HLOS.
  *
  * Copyright (c), 2018, Andrey Warkentin <andrey.warkentin@gmail.com>
  * Copyright (c), Microsoft Corporation. All rights reserved.
@@ -16,7 +16,7 @@
  */
 
 //
-// Description: This is ArasanSD 3.0 SD Host Controller
+// Description: This is ArasanSD 3.0 SD Host Controller.
 //
 
 Device (SDC1)
@@ -43,7 +43,7 @@ Device (SDC1)
     //
     // A child device that represents the
     // sd card, which is marked as non-removable.
-    // 
+    //
     Device (SDMM)
     {
         Method (_ADR)
@@ -56,3 +56,46 @@ Device (SDC1)
         }
     }
 }
+
+
+//
+// Description: This is Broadcom SDHost 2.0 SD Host Controller
+//
+
+Device (SDC2)
+{
+    Name (_HID, "BCM2855")
+    Name (_CID, "SDHST")
+    Name (_UID, 0x0)
+    Name (_S1D, 0x1)
+    Name (_S2D, 0x1)
+    Name (_S3D, 0x1)
+    Name (_S4D, 0x1)
+    Method (_STA)
+    {
+        Return(0xf)
+    }
+    Method (_CRS, 0x0, NotSerialized) {
+        Name (RBUF, ResourceTemplate () {
+            MEMORY32FIXED(ReadWrite, 0x3F202000, 0x100, )
+            Interrupt(ResourceConsumer, Level, ActiveHigh, Exclusive) { 0x58 }
+        })
+        Return(RBUF)
+    }
+
+    //
+    // A child device that represents the
+    // sd card, which is marked as non-removable.
+    // 
+    Device (SDMM)
+    {
+        Method (_ADR)
+        {
+            Return (0)
+        }
+        Method (_RMV) // Is removable
+        {
+            Return (0) // 0 - fixed
+        }
+    }
+}