soc: bcm: brcmstb: biuctrl: Update programming for 7211

Add a matching entry for 7211 which can be programmed with the same
BIUCTRL settings as other Brahma-B53 based SoCs. While at it, rename the
function to include a72 in the name to reflect this applies to both
types of 64-bit capable CPUs that we support (Brahma-B53 and
Cortex-A72).

Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>