fix(ras): remove RAS_FFH_SUPPORT and introduce FFH_SUPPORT

This patch removes RAS_FFH_SUPPORT macro which is the combination of
ENABLE_FEAT_RAS and HANDLE_EA_EL3_FIRST_NS. Instead introduce an
internal macro FFH_SUPPORT which gets enabled when platforms wants
to enable lower EL EA handling at EL3. The internal macro FFH_SUPPORT
will be automatically enabled if HANDLE_EA_EL3_FIRST_NS is enabled.
FFH_SUPPORT along with ENABLE_FEAT_RAS will be used in source files
to provide equivalent check which was provided by RAS_FFH_SUPPORT
earlier. In generic code we needed a macro which could abstract both
HANDLE_EA_EL3_FIRST_NS and RAS_FFH_SUPPORT macros that had limitations.
Former was tied up with NS world only while the latter was tied to RAS
feature.

This is to allow Secure/Realm world to have their own FFH macros
in future.

Signed-off-by: Manish Pandey <manish.pandey2@arm.com>
Change-Id: Ie5692ccbf462f5dcc3f005a5beea5aa35124ac73
diff --git a/docs/getting_started/build-options.rst b/docs/getting_started/build-options.rst
index 51c5c78..43b13d6 100644
--- a/docs/getting_started/build-options.rst
+++ b/docs/getting_started/build-options.rst
@@ -811,17 +811,13 @@
 -  ``PSCI_OS_INIT_MODE``: Boolean flag to enable support for optional PSCI
    OS-initiated mode. This option defaults to 0.
 
--  ``ENABLE_FEAT_RAS``: Numeric value to enable Armv8.2 RAS features. RAS features
+-  ``ENABLE_FEAT_RAS``: Boolean flag to enable Armv8.2 RAS features. RAS features
    are an optional extension for pre-Armv8.2 CPUs, but are mandatory for Armv8.2
    or later CPUs. This flag can take the values 0 or 1. The default value is 0.
    NOTE: This flag enables use of IESB capability to reduce entry latency into
    EL3 even when RAS error handling is not performed on the platform. Hence this
    flag is recommended to be turned on Armv8.2 and later CPUs.
 
--  ``RAS_FFH_SUPPORT``: Support to enable Firmware first handling of RAS errors
-   originating from NS world. When ``RAS_FFH_SUPPORT`` is set to ``1``,
-   ``HANDLE_EA_EL3_FIRST_NS`` and ``ENABLE_FEAT_RAS`` must also be set to ``1``.
-
 -  ``RESET_TO_BL31``: Enable BL31 entrypoint as the CPU reset vector instead
    of the BL1 entrypoint. It can take the value 0 (CPU reset to BL1
    entrypoint) or 1 (CPU reset to BL31 entrypoint).