python: Fix incorrect prefixes is m5.utils.convert

The conversion functions incorrectly assumed that kibibytes are 'kiB'
rather than 'KiB' (correct).

Cherry-picked from:
https://gem5-review.googlesource.com/c/public/gem5/+/39375

Change-Id: Ia9409218c37284514fc4fabdabf327641db8cefc
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/43146
Reviewed-by: Jason Lowe-Power <power.jg@gmail.com>
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>
Maintainer: Jason Lowe-Power <power.jg@gmail.com>
Tested-by: kokoro <noreply+kokoro@google.com>

src/python/m5/util/convert.py

@@ -62,7 +62,7 @@ metric_prefixes = {
     'Gi': gibi,
     'G': giga,
     'M': mega,
-    'ki': kibi,
+    'Ki': kibi,
     'k': kilo,
     'Mi': mebi,
     'm': milli,
@@ -84,7 +84,7 @@ binary_prefixes = {
     'G' : gibi,
     'Mi': mebi,
     'M' : mebi,
-    'ki': kibi,
+    'Ki': kibi,
     'k' : kibi,
 }