SoC: qcom: add support for SDM845

Hi-end qualcomm chip, introduced in late 2017.
Mostly used in flagship phones and tablets of 2018.
Features:
- arm64 arch
- total of 8 Kryo 385 Gold / Silver cores
- Hexagon 685 DSP
- Adreno 630 GPU

Tested only as second-stage bootloader.

Signed-off-by: Dzmitry Sankouski <dsankouski@gmail.com>
Cc: Ramon Fried <rfried.dev@gmail.com>
Cc: Tom Rini <trini@konsulko.com>
Cc: Stephan Gerhold <stephan@gerhold.net>
diff --git a/arch/arm/mach-snapdragon/Kconfig b/arch/arm/mach-snapdragon/Kconfig
index 0ec74fa..1a6a608 100644
--- a/arch/arm/mach-snapdragon/Kconfig
+++ b/arch/arm/mach-snapdragon/Kconfig
@@ -9,6 +9,10 @@
 config SPL_SYS_MALLOC_F_LEN
 	default 0x2000
 
+config SDM845
+	bool "Qualcomm Snapdragon 845 SoC"
+	default n
+
 choice
 	prompt "Snapdragon board select"