omap: Update and rename common defconfig for omap2plus devices

This patch addresses below things

- Renaming existing omap3_defconfig which has OMAP2, OMAP3 and OMAP4 builds
  enabled to more appropriate name 'omap2plus_defconfig'
- L1 cache shift is suppose to be 5 on OMAP4 where as it is 6 on previous
  OMAPs. Keeping it to 5 is safer option for OMAP4 and previous OMAPs. For
  OMAP3 only build the shift would be still 6
- Enable needed Errata's for OMAP4 to work with DMA based device drivers
	CONFIG_PL310_ERRATA_588369=y
	CONFIG_ARM_ERRATA_720789=y
- Enable the Micrel ethernet controller
	CONFIG_KS8851=y
	CONFIG_KS8851_MLL=y

With above three changes, OMAP4 ethernet, mmc etc works reliably.
Signed-off-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>

arch/arm/configs/omap3_defconfig → arch/arm/configs/omap2plus_defconfig

@@ -53,6 +53,7 @@ CONFIG_MACH_SBC3530=y
 CONFIG_MACH_OMAP_3630SDP=y
 CONFIG_MACH_OMAP_4430SDP=y
 CONFIG_ARM_THUMBEE=y
+CONFIG_ARM_L1_CACHE_SHIFT=5
 CONFIG_NO_HZ=y
 CONFIG_HIGH_RES_TIMERS=y
 CONFIG_SMP=y
@@ -139,6 +140,8 @@ CONFIG_SMSC_PHY=y
 CONFIG_NET_ETHERNET=y
 CONFIG_SMC91X=y
 CONFIG_SMSC911X=y
+CONFIG_KS8851=y
+CONFIG_KS8851_MLL=y
 CONFIG_LIBERTAS=y
 CONFIG_LIBERTAS_USB=y
 CONFIG_LIBERTAS_SDIO=y

arch/arm/mach-omap2/Kconfig

@@ -35,7 +35,7 @@ config ARCH_OMAP3
 	default y
 	select CPU_V7
 	select USB_ARCH_HAS_EHCI
-	select ARM_L1_CACHE_SHIFT_6
+	select ARM_L1_CACHE_SHIFT_6 if !ARCH_OMAP4
 
 config ARCH_OMAP4
 	bool "TI OMAP4"
@@ -43,6 +43,8 @@ config ARCH_OMAP4
 	depends on ARCH_OMAP2PLUS
 	select CPU_V7
 	select ARM_GIC
+	select PL310_ERRATA_588369
+	select ARM_ERRATA_720789
 
 comment "OMAP Core Type"
 	depends on ARCH_OMAP2