ARM: 7383/1: nommu: populate vectors page from paging_init

Commit 94e5a85b ("ARM: earlier initialization of vectors page") made it
the responsibility of paging_init to initialise the vectors page.

This patch adds a call to early_trap_init for the !CONFIG_MMU case,
placing the vectors at CONFIG_VECTORS_BASE.

Cc: Jonathan Austin <jonathan.austin@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>