feat(mpam): test FEAT_MPAM_PE_BW_CTRL register access

This patch introduces FEAT_MPAM_PE_BW_CTRL testing to cpu feats.
We check the presence of registers MPAMBW2_EL2, MPAMBW1_EL1
and MPAMBWIDR_EL1 to verify FEAT_MPAM_PE_BW_CTRL
is supported.

Change-Id: I5f89402e8aa0ce3320f3e120f4c0c9dbed6f8c5f
Signed-off-by: Arvind Ram Prakash <arvind.ramprakash@arm.com>
6 files changed