cheshire_pkg: Fix CVA6 debug module addresses

This fixes two errors in the debug module addresses passed to CVA6:

1. `HaltAddress` and `ExceptionAddress` are assumed to be relative to
`DmBaseAddress`, see
https://github.com/pulp-platform/cva6/blob/99ae53bde1a94b90c1d9bbbe7fe272a9336200a6/core/frontend/frontend.sv#L380
and
https://github.com/pulp-platform/cva6/blob/99ae53bde1a94b90c1d9bbbe7fe272a9336200a6/core/csr_regfile.sv#L2295.
Coincidentally, this currently does not cause any issues since `AmDbg = '0`,

2. `ExceptionAddress` was changed from `0x808` to `0x810` in
pulp-platform/riscv-dbg#145, which is included
in the debug module version used in Cheshire. This means that exceptions
in debug mode currently cause CVA6 to jump to `resume` and return from
debug mode instead of handling the exception, which breaks several
openocd commands that use exceptions to discover CSR availabilities.

Signed-off-by: Nils Wistoff <[email protected]>

hw/cheshire_pkg.sv

@@ -493,8 +493,8 @@ package cheshire_pkg;
     ret.AxiIdWidth            = Cva6IdWidth;
     ret.AxiUserWidth          = cfg.AxiUserWidth;
     ret.DmBaseAddress         = AmDbg;
-    ret.HaltAddress           = AmDbg + 'h800;
-    ret.ExceptionAddress      = AmDbg + 'h808;
+    ret.HaltAddress           = 'h800; // Relative to AmDbg
+    ret.ExceptionAddress      = 'h810; // Relative to AmDbg
     ret.NrNonIdempotentRules  = 2;   // Periphs, ExtNonCI;
     ret.NonIdempotentAddrBase = {64'h0000_0000, NoCieBase};
     ret.NOCType               = config_pkg::NOC_TYPE_AXI4_ATOP;