Remove duplicate type declarations for mem_read

These used to be different because they had different effects annotations, but those have since been removed and now they are the same.

model/riscv_mem.sail

@@ -136,18 +136,10 @@ val rvfi_read : forall 'n, 'n > 0. (xlenbits, int('n), MemoryOpResult((bits(8 *
 function rvfi_read (addr, width, result) = ()
 $endif
 
-/* NOTE: The rreg effect is due to MMIO. */
-$ifdef RVFI_DII
 val mem_read      : forall 'n, 0 < 'n <= max_mem_access . (AccessType(ext_access_type), xlenbits, int('n), bool, bool, bool)       -> MemoryOpResult(bits(8 * 'n))
 val mem_read_priv : forall 'n, 0 < 'n <= max_mem_access . (AccessType(ext_access_type), Privilege, xlenbits, int('n), bool, bool, bool)       -> MemoryOpResult(bits(8 * 'n))
 val mem_read_meta : forall 'n, 0 < 'n <= max_mem_access . (AccessType(ext_access_type), xlenbits, int('n), bool, bool, bool, bool) -> MemoryOpResult((bits(8 * 'n), mem_meta))
 val mem_read_priv_meta : forall 'n, 0 < 'n <= max_mem_access . (AccessType(ext_access_type), Privilege, xlenbits, int('n), bool, bool, bool, bool) -> MemoryOpResult((bits(8 * 'n), mem_meta))
-$else
-val mem_read      : forall 'n, 0 < 'n <= max_mem_access . (AccessType(ext_access_type), xlenbits, int('n), bool, bool, bool)       -> MemoryOpResult(bits(8 * 'n))
-val mem_read_priv : forall 'n, 0 < 'n <= max_mem_access . (AccessType(ext_access_type), Privilege, xlenbits, int('n), bool, bool, bool)       -> MemoryOpResult(bits(8 * 'n))
-val mem_read_meta : forall 'n, 0 < 'n <= max_mem_access . (AccessType(ext_access_type), xlenbits, int('n), bool, bool, bool, bool) -> MemoryOpResult((bits(8 * 'n), mem_meta))
-val mem_read_priv_meta : forall 'n, 0 < 'n <= max_mem_access . (AccessType(ext_access_type), Privilege, xlenbits, int('n), bool, bool, bool, bool) -> MemoryOpResult((bits(8 * 'n), mem_meta))
-$endif
 
 /* The most generic memory read operation */
 function mem_read_priv_meta (typ, priv, paddr, width, aq, rl, res, meta) = {