ARM: 8942/1: Revert "8857/1: efi: enable CP15 DMB instructions before cleaning the cache"

This reverts commit e17b1af9, which is
no longer necessary now that the v7 specific routines take care not to
issue CP15 barrier instructions before they are enabled in SCTLR.

Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>