Align microcode location in kernel-install with systemd
https://gitlab.archlinux.org/archlinux/mkinitcpio/mkinitcpio/-/blob/master/kernel-install/40-microcode.install#L19 installs to "${KERNEL_INSTALL_STAGING_AREA}/microcode-${microcode}"
90-loaderentry.install
expects "${KERNEL_INSTALL_STAGING_AREA}"/microcode*
which would work https://github.com/systemd/systemd/blob/23bef849d917f6c0abc82cd795a5622df6494903/src/kernel-install/90-loaderentry.install.in#L157
But latest changes in 60-ukify.install
(included in upcoming 255) now looking for microcode/*
(a subfolder): https://github.com/systemd/systemd/commit/f3d1d7609d2008086f0f8369d9f842a5c09024b2