Merge patch the fixes from "riscv: 64-bit NOMMU fixes and enhancements"

Merge patch the fixes from "riscv: 64-bit NOMMU fixes and enhancements"

These two patches are fixes that the feature depends on, but they also
fix generic issues.  So I'm picking them up for fixes as well as
for-next.

* commit 'aea702dde7e9876fb00571a2602f25130847bf0f':
  riscv: Fix loading 64-bit NOMMU kernels past the start of RAM
  riscv: Fix TASK_SIZE on 64-bit NOMMU

Link: https://lore.kernel.org/r/20240227003630.3634533-1-samuel.holland@sifive.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>