arm: Enable static-pie support (BZ 34098)

arm: Enable static-pie support (BZ 34098)

It requires proper gcc support [1], and without proper compiler support
the arm configure disable static-pie support.

The start.S requires some adjustment to avoid loading main from
the GOT.

Checked on arm-linux-gnueabihf with and without the gcc patch applied.

[1] https://gcc.gnu.org/pipermail/gcc-patches/2022-July/598610.html

Reviewed-by: Yury Khrustalev <yury.khrustalev@arm.com>
Reviewed-by: Sam James <sam@gentoo.org>