scsi: ufs: fix the setting interrupt aggregation counter

IACTH(Interrupt aggregation counter threshold) value is allowed
up to 0x1F and current setting value is the maximum.
This value is related with NUTRS(max:0x20) of HCI's capability.
Considering HCI controller doesn't support the maximum, IACTH
setting should be adjusted with possible value.
For that, existing 'ufshcd_config_int_aggr' is split into two part
[reset, configure].

Change-Id: I9aa56a748612c69a92e0be0d17728eef9e3563ad
Signed-off-by: Seungwon Jeon <tgih.jun@samsung.com>
Reviewed-by: Subhash Jadavani <subhashj@codeaurora.org>
[sthumma@codeaurora.org: fix trivial merge conflicts]
Patch-mainline: linux-scsi@vger.kernel.org @ 2013/08/26, 14:40
Signed-off-by: Sujit Reddy Thumma <sthumma@codeaurora.org>