arm64: renesas: Convert boards over to is_cortex_a() functions

Use generic is_cortex_a() functions instead of open-coded midr_el1 read.
No functional change.

Reviewed-by: Paul Barker <paul.barker.ct@bp.renesas.com>
Signed-off-by: Marek Vasut <marek.vasut+renesas@mailbox.org>
2 files changed