docs: perf: Address some html build warnings

Fix following html build warnings:
Documentation/admin-guide/perf/hisi-pmu.rst:61: WARNING: Unexpected indentation.
Documentation/admin-guide/perf/hisi-pmu.rst:62: WARNING: Block quote ends without a blank line; unexpected unindent.
Documentation/admin-guide/perf/hisi-pmu.rst:69: WARNING: Unexpected indentation.
Documentation/admin-guide/perf/hisi-pmu.rst:70: WARNING: Block quote ends without a blank line; unexpected unindent.
Documentation/admin-guide/perf/hisi-pmu.rst:83: WARNING: Unexpected indentation.

Fixes: 9b86b1b41e0f ("docs: perf: Add new description on HiSilicon uncore PMU v2")
Reported-by: Stephen Rothwell <[e-mail]>
Signed-off-by: Qi Liu <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Will Deacon <[e-mail]>

Documentation/admin-guide/perf/hisi-pmu.rst

···
 as PMU v1, but some new functions are added to the hardware.
 
 (a) L3C PMU supports filtering by core/thread within the cluster which can be
-specified as a bitmap.
+specified as a bitmap::
+
   $# perf stat -a -e hisi_sccl3_l3c0/config=0x02,tt_core=0x3/ sleep 5
+
 This will only count the operations from core/thread 0 and 1 in this cluster.
 
 (b) Tracetag allow the user to chose to count only read, write or atomic
 operations via the tt_req parameeter in perf. The default value counts all
 operations. tt_req is 3bits, 3'b100 represents read operations, 3'b101
 represents write operations, 3'b110 represents atomic store operations and
-3'b111 represents atomic non-store operations, other values are reserved.
+3'b111 represents atomic non-store operations, other values are reserved::
+
   $# perf stat -a -e hisi_sccl3_l3c0/config=0x02,tt_req=0x4/ sleep 5
+
 This will only count the read operations in this cluster.
 
 (c) Datasrc allows the user to check where the data comes from. It is 5 bits.
···
 5'b10000: comes from cross-socket DDR;
 etc, it is mainly helpful to find that the data source is nearest from the CPU
 cores. If datasrc_cfg is used in the multi-chips, the datasrc_skt shall be
-configured in perf command.
+configured in perf command::
+
   $# perf stat -a -e hisi_sccl3_l3c0/config=0xb9,datasrc_cfg=0xE/,
   hisi_sccl3_l3c0/config=0xb9,datasrc_cfg=0xF/ sleep 5