ARM: OMAP: Add a timer attribute for timers that can interrupt the DSP

Some instances of the DMTIMER peripheral on OMAP devices have the ability
to interrupt the on-chip DSP in addition to the ARM CPU. Add a DMTIMER
attribute to indicate which timers can interrupt the DSP. By using the
omap_dm_timer_request_by_cap() API, driver will now be able to allocate
a DMTIMER that can interrupt the DSP based upon this attribute and not require
the driver to know which instance has this capability.

DMTIMERs that have the ability to interrupt the DSP on OMAP devices are as
follows ...

- OMAP1 (OMAP5912/16xx/17xx) devices	- All 8 DMTIMERs
- OMAP2/3/4 devices			- DMTIMERs 5-8

Please note that for OMAP3+, timer8 has the ability to interrupt the DSP and
generate a PWM output.

Signed-off-by: Jon Hunter <jon-hunter@ti.com>
Signed-off-by: Paul Walmsley <paul@pwsan.com>

arch/arm/plat-omap/include/plat/dmtimer.h

@@ -60,6 +60,7 @@
 #define OMAP_TIMER_ALWON				0x40000000
 #define OMAP_TIMER_HAS_PWM				0x20000000
 #define OMAP_TIMER_NEEDS_RESET				0x10000000
+#define OMAP_TIMER_HAS_DSP_IRQ				0x08000000
 
 struct omap_timer_capability_dev_attr {
 	u32 timer_capability;