coresight: trbe: fix Kconfig "its" grammar

coresight: trbe: fix Kconfig "its" grammar

Use the possessive "its" instead of the contraction "it's"
where appropriate.

Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: Suzuki K Poulose <suzuki.poulose@arm.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: coresight@lists.linaro.org
Cc: linux-arm-kernel@lists.infradead.org
Link: https://lore.kernel.org/r/20220715015925.12569-1-rdunlap@infradead.org
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>