ARM: mach-omap2: omap3/am335x: Enable ACR::IBE on Cortex-A8 SoCs for CVE-2017-5715

Enable CVE-2017-5715 option to set the IBE bit. This enables kernel
workarounds necessary for the said CVE.

With this enabled, Linux reports:
CPU0: Spectre v2: using BPIALL workaround

This workaround may need to be re-applied in OS environment around low
power transition resume states where context of ACR would be lost (off-mode
etc).
Signed-off-by: NNishanth Menon <nm@ti.com>

arch/arm/mach-omap2/Kconfig

@@ -10,6 +10,7 @@ config OMAP34XX
 	select ARM_ERRATA_454179
 	select ARM_ERRATA_621766
 	select ARM_ERRATA_725233
+	select ARM_CORTEX_A8_CVE_2017_5715
 	select USE_TINY_PRINTF
 	imply NAND_OMAP_GPMC
 	imply SPL_EXT_SUPPORT
@@ -116,6 +117,7 @@ config AM43XX
 config AM33XX
 	bool "AM33XX SoC"
 	select SPECIFY_CONSOLE_INDEX
+	select ARM_CORTEX_A8_CVE_2017_5715
 	imply NAND_OMAP_ELM
 	imply NAND_OMAP_GPMC
 	imply SPL_NAND_AM33XX_BCH