[PARISC] Use F_EXTEND() for COMMAND_GLOBAL

Instead of wrapping the define of COMMAND_GLOBAL in #ifdef __LP64__
use the F_EXTEND() macro defined in asm/io.h, which is the preferred
way of extending mmio space addresses for either 32 or 64 bit machines.
Signed-off-by: Kyle McMartin <kyle@parisc-linux.org>

arch/parisc/kernel/process.c

@@ -102,12 +102,7 @@ void cpu_idle(void)
 }
 
 
-#ifdef __LP64__
-#define COMMAND_GLOBAL  0xfffffffffffe0030UL
-#else
-#define COMMAND_GLOBAL  0xfffe0030
-#endif
-
+#define COMMAND_GLOBAL  F_EXTEND(0xfffe0030)
 #define CMD_RESET       5       /* reset any module */
 
 /*