OMAP2+: hwmod: fix incorrect computation of autoidle_mask

Autoidle is a single bit, TIOCP_CFG[0], setting on OMAP1/2/3/4 platforms.
In _set_module_autoidle() I am seeing 0x3 value where the mask is computed.
This should be 0x1.

v2:
(1) Modified the subject.
(2) Modified the description with further specific information.

Baseline:
git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6.git

Tested Info:
Boot tested on OMAP 1/2/3/4.

Signed-off-by: Tarun Kanti DebBarma <tarun.kanti@ti.com>
Acked-by: Rajendra Nayak <rnayak@ti.com>
Acked-by: Benoit Cousson <b-cousson@ti.com>
Signed-off-by: Paul Walmsley <paul@pwsan.com>