mailbox: bcm-flexrm-mailbox: Fix mask used in CMPL_START_ADDR_VALUE()

mailbox: bcm-flexrm-mailbox: Fix mask used in CMPL_START_ADDR_VALUE()

commit 6d2061b981af165d3e45462e0804b5a1f2f4c7bc upstream.

The mask used in CMPL_START_ADDR_VALUE() should be 27bits instead of
26bits. This incorrect mask was causing completion writes to 40bits
physical address fail.

This patch fixes mask used in CMPL_START_ADDR_VALUE() macro.

Fixes: dbc049eee730 ("mailbox: Add driver for Broadcom FlexRM
ring manager")

Signed-off-by: Anup Patel <anup.patel@broadcom.com>
Reviewed-by: Ray Jui <ray.jui@broadcom.com>
Reviewed-by: Scott Branden <scott.branden@broadcom.com>
Signed-off-by: Jassi Brar <jaswinder.singh@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>