arm64: Cleanup __cpu_set_tcr_t0sz()

arm64: Cleanup __cpu_set_tcr_t0sz()

The T0SZ field of TCR_EL1 occupies bits 0-5 of the register and encode
the virtual address space translated by TTBR0_EL1. When updating the
field, for example because we are switching to/from the idmap page-table,
__cpu_set_tcr_t0sz() erroneously treats its 't0sz' argument as unshifted,
resulting in harmless but confusing double shifts by 0 in the code.

Co-developed-by: Leem ChaeHoon <[email protected]>
Signed-off-by: Leem ChaeHoon <[email protected]>
Signed-off-by: Seongsu Park <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Catalin Marinas <[email protected]>