armv8: Fix TCR macros for shareability attribute

For ARMv8, outer shareable is 0b10, inner shareable is 0b11 at bit
position [13:12] of TCR_ELx register.

Signed-off-by: Zhichun Hua <zhichun.hua@freescale.com>
Signed-off-by: York Sun <yorksun@freescale.com>