Put both OMAP5 cores into HYP mode

[vs: rebase, add '.arch_extension sec' directives to fix compilation]
Signed-off-by: Vincent Stehlé <v-stehle@ti.com>
Fix omap5 hyp mode for second cpu

Make it work on PandaBoard 5 with 5432 ES2 and Linux.

Signed-off-by: Vincent Stehlé <v-stehle@ti.com>