Add depends 32-bit arm support for bitcoin-qt

Summary:
Some hobbyists are used to using the desktop for interfacing with their
raspberry pi. This commits adds qt to the arm-linux-gnueabihf target.

depends: use MacOS friendly sed syntax in qt.mk

This is a backport of Core's PR13604 and PR13750

Depends on D1820

Test Plan:

make -C ../depends build-all

Reviewers: #bitcoin_abc, jasonbcox

Reviewed By: #bitcoin_abc, jasonbcox

Subscribers: teamcity

Differential Revision: https://reviews.bitcoinabc.org/D1821