vme: vme_ca91cx42.c: local functions should not be exposed globally

Functions not referenced outside of a source file should be marked
static to prevent them from being exposed globally.

Quiets the sparse warnings:

warning: symbol 'ca91cx42_alloc_consistent' was not declared. Should it be static?
warning: symbol 'ca91cx42_free_consistent' was not declared. Should it be static?

Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Acked-by: Martyn Welch <martyn.welch@ge.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>