scripts/checkstack.pl: match all stack sizes for some archs

For some unknown reason the regular expression for checkstack only matches
three digit numbers starting with the number "3", or any higher number. 
Which means that it skips any stack sizes smaller than 304 bytes.  This
makes the checkstack script a bit less useful than it could be.

Change the script to match any number.  To be filtered out stack sizes can
be configured with the min_stack variable, which omits any stack frame
sizes smaller than 100 bytes by default.

This is similar with commit aab1f809 ("scripts/checkstack.pl: match
all stack sizes for s390").

Link: https://lkml.kernel.org/r/20231219125008.23007-4-yangtiezhu@loongson.cn


Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Cc: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>