ARM: vfp: fix fpsid register subarchitecture field mask width

The subarchitecture field in the fpsid register is 7 bits wide.
The topmost bit is used to designate that the subarchitecture
designer is not ARM.

This change has the side effect of causing VFP implementations
other than ARM to be reported as VFPv3 with common VFP subarch
v3. Before this change it would be reported as VFPv1 with
an implementation defined subarchitecture.

CRs-Fixed: 268685
Change-Id: If304d284e2a104202b617ede86942bc89de0fb45
Signed-off-by: Steve Muckle <smuckle@codeaurora.org>