OMAP4: HSI: Add dynamic OPP change

Added an IOCTL to change HSI FClk to 96MHz or 192MHz.
Decision of when to increase/decrease modem speed is up to Link Layer.

Constraint :
* RX/TX divisors and RX error counters need to be changed after Fclk is changed.
* Read/Write operation must not be pending when OPP change request is issued, otherwise
OPP change is aborted.
* Any Read/Write operation started during HSI OPP change operation will be aborted.

Change-Id: I06e15a205e614506994989ec6a40c0383e32776d
Signed-off-by: Djamil Elaidi <d-elaidi@ti.com>
OMAP4: DPLL cascading: usage of DPLL cascading blocker API on HSI activity

When HSI driver is probed, it sets a constraint to keep HSI Fclk at 96 MHz.
But this constraint was not released, thus it was not possible to enter
OPPLP (used for DPLL cascading).

Now DPLL cascading blocker constraint is set and release based on HSI
activity.

[Andrii Tseglytskyi <andrii.tseglytskyi@ti.com>:
Ported and adapted to p-android-omap-3.0]

Change-Id: Id8ace8f8a4f0a24641e51023346a745ecaaaf423
Signed-off-by: Djamil Elaidi <d-elaidi@ti.com>
Signed-off-by: Andrii Tseglytskyi <andrii.tseglytskyi@ti.com>
OMAP4+: HSI: Aligned HSR FSM control onto CAWAKE detection

HSR FSM enables the ACREADY to go to 1 and allows reception.
With previous code, HSR FSM is enabled/disabled when clocks are enabled/disabled.
But HSR FSM control shall be separated from HST state, and depend only on CAWAKE.

Now HSR FSM is disabled/enabled when CAWAKE is low/high.

Change-Id: I527bc0cc376218abd01d4e1c6cda2487ce0ecf27
Signed-off-by: Djamil Elaidi <d-elaidi@ti.com>

Conflicts:
	drivers/omap_hsi/hsi_driver.c
Revert "OMAP4+: HSI: Aligned HSR FSM control onto CAWAKE detection"

This reverts commit ec3d4dfb31b8519bac879d12bc9900dc6b3ef3d6.