ARM: 7346/1: errata: fix PL310 erratum #753970 workaround selection

Commit fa0ce403 ("ARM: 7162/1: errata: tidy up Kconfig options for PL310
errata workarounds") introduced a consistent naming scheme for errata
workarounds, but forgot to update the platforms selecting workarounds
using the old names.

This patch updates ux500 and vexpress to select the appropriate PL310
errata workarounds.

Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>