MIPS: Clean up the calculation of VMLINUZ_LOAD_ADDRESS

We have calculated VMLINUZ_LOAD_ADDRESS in shell, which is indecipherable. This
patch rewrites it in C.

Signed-off-by: Wu Zhangjin <wuzhangjin@gmail.com>
To: linux-mips <linux-mips@linux-mips.org>
Cc: Alexander Clouter <alex@digriz.org.uk>
Cc: Manuel Lauss <manuel.lauss@gmail.com>
Cc: Sam Ravnborg <sam@ravnborg.org>
Acked-by: Sam Ravnborg <sam@ravnborg.org>
Reviewed-by: Alexander Clouter <alex@digriz.org.uk>
Patchwork: https://patchwork.linux-mips.org/patch/1324/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
diff --git a/arch/mips/boot/.gitignore b/arch/mips/boot/.gitignore
index 4667a5f..f210b09 100644
--- a/arch/mips/boot/.gitignore
+++ b/arch/mips/boot/.gitignore
@@ -3,3 +3,4 @@
 vmlinux.*
 zImage
 zImage.tmp
+calc_vmlinuz_load_addr