Added an underscore to _ARM_HAVE_LDREX_STREX to make it match the others.
Added __ARM_HAVE_DMB and __ARM_HAVE_LDREXD when appropriate.
Fixed some typos.
Change-Id: I2f55febcff4aeb7de572a514fb2cd2f820dca27c
ARMv6 onwards. These architectures provide the load-linked, store-conditional pair of ldrex/strex whose use
is recommended in place of 'swp'. Also, the description of the 'swp' instruction in the ARMv6 reference
manual states that the swap operation does not include any memory barrier guarantees.This fix attempts to
address these issues by providing an atomic swap implementation using ldrex/strex under _ARM_HAVE_LDREX_STREX
macro. This Fix is verified on ST Ericsson's U8500 platform and Submitted on behalf of a third-party:
Surinder-pal SINGH from STMicroelectronics.
