gma registers: Add generic Wait() procedure

Add a more generic Wait() procedure that waits for some masked bits of
a register to hold a specific value.

Change-Id: Iafefce3da8907e7edf00c68e7a8b650aa7bcd372
Signed-off-by: Nico Huber <nico.huber@secunet.com>
Reviewed-on: https://review.coreboot.org/18419
Tested-by: Nico Huber <nico.h@gmx.de>
Reviewed-by: Arthur Heymans <arthur@aheymans.xyz>
diff --git a/common/hw-gfx-gma-registers.ads b/common/hw-gfx-gma-registers.ads
index 68763c8..9b32c63 100644
--- a/common/hw-gfx-gma-registers.ads
+++ b/common/hw-gfx-gma-registers.ads
@@ -1075,6 +1075,13 @@
 
    pragma Warnings (GNATprove, Off, "unused initial value of ""Verbose""",
                     Reason => "Only used on debugging path");
+   procedure Wait
+     (Register : Registers_Index;
+      Mask     : Word32;
+      Value    : Word32;
+      TOut_MS  : Natural := Default_Timeout_MS;
+      Verbose  : Boolean := False);
+
    procedure Wait_Set_Mask
       (Register : Registers_Index;
        Mask     : Word32;