i2c: isch: Remove unnecessary acpi.h include

i2c: isch: Remove unnecessary acpi.h include

Commit 68c1195d18c3 ("i2c: Check for ACPI resource conflicts") included
<linux/acpi.h> so we could use acpi_check_region(). Commit 8af45c821678
("i2c: convert i2c-isch to platform_device") removed the use of
acpi_check_region() but not the include.

Remove the now-unnecessary include of <linux/acpi.h>.  No functional change
intended.

Fixes: 8af45c821678 ("i2c: convert i2c-isch to platform_device")
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Jean Delvare <jdelvare@suse.de>
Reviewed-by: Mukesh Ojha <mojha@codeaurora.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>