CPU (Linux): make Snapdragon X1/X2 detection more correct (#2625)

Use the previously discussed soc_id which have public values in EDK2.

The so far used toplevel devicetree compatible values weren't as precise
and some logic (x1, x2p, x2e) simply was dead code.

Also drops the CPU test due to reading soc_id sysfs file, could be
adapted if still wanted around.

CMakeLists.txt

@@ -2276,15 +2276,6 @@ if (BUILD_TESTS)
         PRIVATE libfastfetch
     )
 
-    if (CMAKE_SYSTEM_NAME STREQUAL "Linux")
-        add_executable(fastfetch-test-cpu
-            tests/cpu.c
-        )
-        target_link_libraries(fastfetch-test-cpu
-            PRIVATE libfastfetch
-        )
-    endif()
-
     add_executable(fastfetch-test-strbuf
         tests/strbuf.c
     )
@@ -2398,9 +2389,6 @@ if (BUILD_TESTS)
     )
 
     enable_testing()
-    if (CMAKE_SYSTEM_NAME STREQUAL "Linux")
-        add_test(NAME test-cpu COMMAND fastfetch-test-cpu)
-    endif()
     add_test(NAME test-cache COMMAND fastfetch-test-cache)
     add_test(NAME test-logo COMMAND fastfetch-test-logo)
     add_test(NAME test-strbuf COMMAND fastfetch-test-strbuf)