feat(sme): add sme helper routines and add streaming sve support

This patch adds a few helper routines to set the Streaming SVE vector
length (SVL) in the SMCR_EL2 register, to enable/disable FEAT_SME_FA64
and to get CPU's Streaming SVE mode status.

This patch also makes SVE compare routines compatible for both normal
SVE and streaming SVE mode.

Signed-off-by: Arunachalam Ganapathy <arunachalam.ganapathy@arm.com>
Change-Id: I7294bb17a85de395a321e99241704066662c90e8
7 files changed