ARM: 8849/1: NOMMU: Fix encodings for PMSAv8's PRBAR4/PRLAR4

To access PRBARn, where n is referenced as a binary number:

MRC p15, 0, <Rt>, c6, c8+n[3:1], 4*n[0] ; Read PRBARn into Rt
MCR p15, 0, <Rt>, c6, c8+n[3:1], 4*n[0] ; Write Rt into PRBARn

To access PRLARn, where n is referenced as a binary number:

MRC p15, 0, <Rt>, c6, c8+n[3:1], 4*n[0]+1 ; Read PRLARn into Rt
MCR p15, 0, <Rt>, c6, c8+n[3:1], 4*n[0]+1 ; Write Rt into PRLARn

For PR{B,L}AR4, n is 4, n[0] is 0, n[3:1] is 2, while current encoding
done with n[0] set to 1 which is wrong. Use proper encoding instead.

Fixes: 046835b4

 ("ARM: 8757/1: NOMMU: Support PMSAv8 MPU")
Signed-off-by: Vladimir Murzin <vladimir.murzin@arm.com>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>