configs: RPi2: Disable EFI Grub workaround

The EFI Grub workaround isn't needed with Grub version 2.04 or higher.
This version was published over a year ago, so disable the workaround
to reduce boot time.

Signed-off-by: Matthias Brugger <mbrugger@suse.com>

configs/rpi_2_defconfig

@@ -42,3 +42,4 @@ CONFIG_SYS_WHITE_ON_BLACK=y
 CONFIG_CONSOLE_SCROLL_LINES=10
 CONFIG_PHYS_TO_BUS=y
 CONFIG_OF_LIBFDT_OVERLAY=y
+# CONFIG_EFI_GRUB_ARM32_WORKAROUND is not set