efi: fdt: Do not report an error during boot if UEFI is not available

Currently, fdt_find_uefi_params() reports an error if no EFI parameters
are found in the DT. This is however a valid case for non-UEFI kernel
booting. This patch checks changes the error reporting to a
pr_info("UEFI not found") when no EFI parameters are found in the DT.

Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Leif Lindholm <leif.lindholm@linaro.org>
Tested-by: Leif Lindholm <leif.lindholm@linaro.org>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>