RISCV: get RISCV to build again

This makes lzmadecode 64-bit clean (I hope).
It also cleans up a few other nits.

Change-Id: I24492e9f357e8d3a6de6abc351267f900eb4a19a
Signed-off-by: Ronald G. Minnich <rminnich@gmail.com>
Reviewed-on: http://review.coreboot.org/7623
Reviewed-by: Edward O'Callaghan <eocallaghan@alterapraxis.com>
Reviewed-by: Patrick Georgi <pgeorgi@google.com>
Tested-by: build bot (Jenkins)
diff --git a/src/lib/lzmadecode.c b/src/lib/lzmadecode.c
index fb57f4f..ada7226 100644
--- a/src/lib/lzmadecode.c
+++ b/src/lib/lzmadecode.c
@@ -20,6 +20,7 @@
 */
 
 #include "lzmadecode.h"
+#include <stdint.h>
 
 #define kNumTopBits 24
 #define kTopValue ((UInt32)1 << kNumTopBits)
@@ -30,7 +31,7 @@
 
 /* Use 32-bit reads whenever possible to avoid bad flash performance.  */
 #define RC_READ_BYTE (look_ahead_ptr < 4 ? look_ahead.raw[look_ahead_ptr++] \
-		      : ((((UInt32) Buffer & 3) || ((SizeT) (BufferLim - Buffer) < 4)) ? (*Buffer++) \
+		      : ((((uintptr_t) Buffer & 3) || ((SizeT) (BufferLim - Buffer) < 4)) ? (*Buffer++) \
 	   : ((look_ahead.dw = *(UInt32 *)Buffer), (Buffer += 4), (look_ahead_ptr = 1), look_ahead.raw[0])))
 
 #define RC_INIT2 Code = 0; Range = 0xFFFFFFFF; \