build: update arm64 minimum supported platform

This is already true in practice.

Backport-PR-URL: #23275
PR-URL: #19164
Fixes: nodejs/build#1164
Reviewed-By: Rod Vagg <rod@vagg.org>
Reviewed-By: Michael Dawson <michael_dawson@ca.ibm.com>

Author: gibfahn

BUILDING.md

@@ -39,7 +39,8 @@ in production.
 
 |  System      | Support type | Version                          | Architectures        | Notes            |
 |--------------|--------------|----------------------------------|----------------------|------------------|
-| GNU/Linux    | Tier 1       | kernel >= 2.6.32, glibc >= 2.12  | x86, x64, arm, arm64 |                  |
+| GNU/Linux    | Tier 1       | kernel >= 2.6.32, glibc >= 2.12  | x86, x64, arm        |                  |
+| GNU/Linux    | Tier 1       | kernel >= 3.10, glibc >= 2.17    | arm64                |                  |
 | macOS        | Tier 1       | >= 10.10                         | x64                  |                  |
 | Windows      | Tier 1       | >= Windows 7 / 2008 R2           | x86, x64             | vs2015 or vs2017 |
 | SmartOS      | Tier 2       | >= 15 < 16.4                     | x86, x64             | see note1        |