script: fix: taking into account decimal value in macro_parser

when a decimal value is used this issue happen:
    nums[i] = int(nums[i], 0)
ValueError: invalid literal for int() with base 0: ''

The regexp of findall returns an empty string for decimal value.
solution: remove or extend the group '()'

Change-Id: Ia159dcc0d16ed44c07925a76272ceebe2136a503
Signed-off-by: Ludovic Barre <ludovic.barre@foss.st.com>
diff --git a/bl2/ext/mcuboot/scripts/macro_parser.py b/bl2/ext/mcuboot/scripts/macro_parser.py
index 12e8a92..77ab6aa 100644
--- a/bl2/ext/mcuboot/scripts/macro_parser.py
+++ b/bl2/ext/mcuboot/scripts/macro_parser.py
@@ -32,7 +32,7 @@
         msg += " (NON-)SECURE_IMAGE_MAX_SIZE macros"
         raise Exception(msg)
 
-    nums = re.findall(r'(0x[A-Fa-f0-9]+)|[\d]+', m.group(0))
+    nums = re.findall(r'0x[A-Fa-f0-9]+|[\d]+', m.group(0))
     for i in range(len(nums)):
         nums[i] = int(nums[i], 0)
     ops = re.findall(r'\+|\-', m.group(0))