ARM: DRA7: Add support for virtual mode configuration

In addition to the regular mux configuration, certain pins of DRA7
require to have "virtual mode" also programmed.
This allows for predefined delay characteristics to be used by the SoC
to meet timing characterstics needed for the interface.

Provide easy to use macro to do the same.

For configuring virtual mode, along with normal pad configuration add
the following two steps:
- Select MODESELECT field of each assocaited PAD.
  CTRL_CORE_PAD_XXX[8]:MODESELECT = 1
- DELAYMODE filed should be configured with value given in DATA Manual.
  CTRL_CORE_PAD_XXX[7:4]:DELAYMODE =[0-15] (as given in DATA manual).

Signed-off-by: Lokesh Vutla <lokeshvutla@ti.com>
Signed-off-by: Nishanth Menon <nm@ti.com>

arch/arm/include/asm/arch-omap5/mux_dra7xx.h

@@ -58,6 +58,26 @@
 #define M14	14
 #define M15	15
 
+#define MODE_SELECT		(1 << 8)
+#define DELAYMODE_SHIFT		4
+
+#define VIRTUAL_MODE0	(MODE_SELECT | (0x0 << DELAYMODE_SHIFT))
+#define VIRTUAL_MODE1	(MODE_SELECT | (0x1 << DELAYMODE_SHIFT))
+#define VIRTUAL_MODE2	(MODE_SELECT | (0x2 << DELAYMODE_SHIFT))
+#define VIRTUAL_MODE3	(MODE_SELECT | (0x3 << DELAYMODE_SHIFT))
+#define VIRTUAL_MODE4	(MODE_SELECT | (0x4 << DELAYMODE_SHIFT))
+#define VIRTUAL_MODE5	(MODE_SELECT | (0x5 << DELAYMODE_SHIFT))
+#define VIRTUAL_MODE6	(MODE_SELECT | (0x6 << DELAYMODE_SHIFT))
+#define VIRTUAL_MODE7	(MODE_SELECT | (0x7 << DELAYMODE_SHIFT))
+#define VIRTUAL_MODE8	(MODE_SELECT | (0x8 << DELAYMODE_SHIFT))
+#define VIRTUAL_MODE9	(MODE_SELECT | (0x9 << DELAYMODE_SHIFT))
+#define VIRTUAL_MODE10	(MODE_SELECT | (0xa << DELAYMODE_SHIFT))
+#define VIRTUAL_MODE11	(MODE_SELECT | (0xb << DELAYMODE_SHIFT))
+#define VIRTUAL_MODE12	(MODE_SELECT | (0xc << DELAYMODE_SHIFT))
+#define VIRTUAL_MODE13	(MODE_SELECT | (0xd << DELAYMODE_SHIFT))
+#define VIRTUAL_MODE14	(MODE_SELECT | (0xe << DELAYMODE_SHIFT))
+#define VIRTUAL_MODE15	(MODE_SELECT | (0xf << DELAYMODE_SHIFT))
+
 #define SAFE_MODE	M15
 
 #define GPMC_AD0	0x000