Remove some trailing HAL support

Detail:
  A few sections of code guarded by USBHAL defines carried over from when this component was split off USBDriver.
  The define is unset, so they can be removed.
Admin:
  Submission for USB bounty.

Version 0.37. Tagged as 'EHCIDriver-0_37'

VersionNum

-/* (0.36)
+/* (0.37)
  *
  * This file is automatically maintained by srccommit, do not edit manually.
  * Last processed by srccommit version: 1.1.
  *
  */
-#define Module_MajorVersion_CMHG        0.36
+#define Module_MajorVersion_CMHG        0.37
 #define Module_MinorVersion_CMHG        
 #define Module_Date_CMHG                19 Sep 2017
 
-#define Module_MajorVersion             "0.36"
-#define Module_Version                  36
+#define Module_MajorVersion             "0.37"
+#define Module_Version                  37
 #define Module_MinorVersion             ""
 #define Module_Date                     "19 Sep 2017"
 
@@ -18,6 +18,6 @@
 #define Module_ComponentName            "EHCIDriver"
 #define Module_ComponentPath            "mixed/RiscOS/Sources/HWSupport/USB/Controllers/EHCIDriver"
 
-#define Module_FullVersion              "0.36"
-#define Module_HelpVersion              "0.36 (19 Sep 2017)"
-#define Module_LibraryVersionInfo       "0:36"
+#define Module_FullVersion              "0.37"
+#define Module_HelpVersion              "0.37 (19 Sep 2017)"
+#define Module_LibraryVersionInfo       "0:37"

h/ehcivar

@@ -36,12 +36,7 @@
  * POSSIBILITY OF SUCH DAMAGE.
  */
 
-#ifdef USBHAL
-/* We have little memory available in the HAL, so allocate in smaller chunks */
-#define EHCI_SMALL_PAGE_SIZE 512
-#else
 #define EHCI_SMALL_PAGE_SIZE EHCI_PAGE_SIZE
-#endif
 #ifdef __riscos
 /* EHCI could use SyncLib for mutex, but for now, just wing it */
 #define mutex_init(a,b,c)
@@ -116,11 +111,7 @@ struct ehci_soft_islot {
 };
 
 #define EHCI_FRAMELIST_MAXCOUNT	1024
-#ifdef USBHAL
-#define EHCI_IPOLLRATES		3 /* Full poll list uses too much memory for HAL. See if this works. */
-#else
 #define EHCI_IPOLLRATES		8 /* Poll rates (1ms, 2, 4, 8 .. 128) */
-#endif
 #define EHCI_INTRQHS		((1 << EHCI_IPOLLRATES) - 1)
 #define EHCI_MAX_POLLRATE	(1 << (EHCI_IPOLLRATES - 1))
 #define EHCI_IQHIDX(lev, pos) \