ARM: tegra: Reserve 32MB for the Linux kernel

Booting recently Linux -next kernels on 32-bit Tegra devices has been
failing when using the 'multi_v7_defconfig' kenrel configuration because
the size of has grown such that it is overwriting the FDT blob.

Current Linux -next kernels built with the 'multi_v7_defconfig' have a
total size of ~19.5MB (where .text is ~12.5MB, .data is ~6.5MB and .bss
is ~0.5MB). Therefore, increase the memory location reserved for the
Linux kernel to 32MB from 16MB for 32-bit Tegra devices.

This change has been boot tested on Tegra20 Ventana, Tegra30 Cardhu and
Tegra124 Jetson TK1 with the Linux next tree (20190212).

Signed-off-by: Jonathan Hunter <jonathanh@nvidia.com>
Reviewed-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Tom Warren <twarren@nvidia.com>