docs: arm: tcm: Fix a few typos

Written by Linus Walleij <linus.walleij@stericsson.com>

Some ARM SoC:s have a so-called TCM (Tightly-Coupled Memory).

Some ARM SoCs have a so-called TCM (Tightly-Coupled Memory).

This is usually just a few (4-64) KiB of RAM inside the ARM

processor.

Due to being embedded inside the CPU The TCM has a

Due to being embedded inside the CPU, the TCM has a

Harvard-architecture, so there is an ITCM (instruction TCM)

and a DTCM (data TCM). The DTCM can not contain any

instructions, but the ITCM can actually contain data.

The size of DTCM or ITCM is minimum 4KiB so the typical

minimum configuration is 4KiB ITCM and 4KiB DTCM.

ARM CPU:s have special registers to read out status, physical

ARM CPUs have special registers to read out status, physical

location and size of TCM memories. arch/arm/include/asm/cputype.h

defines a CPUID_TCM register that you can read out from the

system control coprocessor. Documentation from ARM can be found