[ARM] arm32: Enable full-access to cp10 & cp11 for ARMv6 and ARMv7

For accessing VFP (i.e. coprocessors cp10 & cp11), we require to enable
cp10 & cp11 access in CPACR register for ARMv6 and ARMv7.

This is required to be done on all host CPUs hence we update cpu_init()
accordingly.

Signed-off-by: Anup Patel <anup@brainfault.org>