omap4: Fix bootup crash observed with higher CPU clocks

This patch is temporary fix to below crash. This is observed when
CPU is clocked more than 600 MHz.

Unhandled fault: imprecise external abort (0x1406) at 0xbf9ef65c
Internal error: : 1406 [#1] PREEMPT SMP
last sysfs file:
Modules linked in:
CPU: 0    Not tainted  (2.6.36-rc3+ #18)
PC is at kernel_thread_helper+0x0/0x14
LR is at kernel_thread_helper+0x0/0x14
pc : [<c003ce14>]    lr : [<c003ce14>]    psr: 00000093
sp : dc83bff8  ip : 00000000  fp : 00000000
r10: 00000000  r9 : 00000000  r8 : 00000000
r7 : 00000013  r6 : c003ce28  r5 : c008935c  r4 : 00000000
r3 : 00000000  r2 : 00000000  r1 : 00000000  r0 : 00000000
Flags: nzcv  IRQs off  FIQs on  Mode SVC_32  ISA ARM  Segment kernel
Control: 10c53c7f  Table: 8000404a  DAC: 00000017
Process swapper (pid: 2, stack limit = 0xdc83a2f0)
Stack: (0xdc83bff8 to 0xdc83c000)
bfe0: 00000000 ffffffff
[<c003ce14>] (kernel_thread_helper+0x0/0x14) from [<fffffffe>] (0xfffffffe)
Code: c03a0ba3 c03a5fcb c045c880 c0394035 (eb017701)
---[ end trace 1b75b31a2719ed1c ]---

The timer hwmod adaptation will eventually fix it in a proper way.
Signed-off-by: NRajendra Nayak <rnayak@ti.com>
Signed-off-by: NSantosh Shilimkar <santosh.shilimkar@ti.com>

arch/arm/plat-omap/dmtimer.c

@@ -581,7 +581,7 @@ int omap_dm_timer_set_source(struct omap_dm_timer *timer, int source)
 	 * When the functional clock disappears, too quick writes seem
 	 * to cause an abort. XXX Is this still necessary?
 	 */
-	__delay(150000);
+	__delay(300000);
 
 	return ret;
 }