i2c: pm_smbus: Don't delay host status register busy bit when interrupts are enabled

i2c: pm_smbus: Don't delay host status register busy bit when interrupts are enabled

Change 880b1ffe6ec2f0ae "smbus: do not immediately complete commands"
changed pm_smbus to delay setting the host busy bit until the status
register was read, to work around a bug in AMIBIOS.  Unfortunately,
when interrupts are enabled, the status register will never get read
and the processing will never happen.

Modify the code to only delay setting the host busy bit if interrupts
are not enabled.

Signed-off-by: Corey Minyard <cminyard@mvista.com>
Cc: Hervé Poussineau <hpoussin@reactos.org>
Cc: Philippe Mathieu-Daudé <f4bug@amsat.org>
Message-Id: <1534796770-10295-8-git-send-email-minyard@acm.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>